Historic tablature: 'grid' of beamed values mixed with symbols.
Following several requests (at the moment I can only find this
and this
, but I remember there were others as well), I am working at implementing the mixture of value symbols and beamed 'grid' of stems found in historic tablatures, like for instance this one (taken from the 1605 Windet print of Dowland's Lachrimæ):
This applies only to the TAB with "Note Values | Shown as" set at "Note symbols"; the other settings do not use symbols at all and either do not have any value indication or always use 'standard' hooks and beams. My current in-progress implementation is at moment like this (several details are still to fix):
The points I am concerned with and the guide lines I am using to approach them are three:
1) Beaming input or how to tell the programme where to use the beaming and where not; for this I decide to use the beaming commands themselves, found in the "Beam Properties" palette. In particular:
- If a chord has "Auto" beaming (the default), it has the same behaviour as now (value symbols, with appropriate symbol repetition and so on).
- If a chord has "Beam start" beaming, it does not use symbols but just a stem and it will be the first element of a beaming group.
- If a chord has "Beam middle" beaming, it does not use symbols but stem and beam(s) and will connect its beam(s) to the previous element.
- If a chord has any other beaming value, it will generate a single value symbol, regardless of repetition settings.
I don't know if (and how) this will affect linked staves (does beaming propagate to linked staves? might different beamings in different linked staves be necessary?). Use cases about this points are welcome.
2) Stem and beam sizes: different symbol styles have a different total height and may require a different stem and beam width.
My idea is to hard-code these three values (stem height, stem width and beam width) in the style definition: when one chooses a note value style, it will bring these values with itself (currently there are three note value styles: Modern, Italian, French, and a couple more are on the way).
3) Beaming level: the number of beams used in historic tablatures does not necessarily correspond to the modern conventions; in fact, in the above Dowland example, one beam applies to minims, two beams to crochets, three beams to quavers and so on.
Again, my approach is to hard-code the beam level in the style definition (so, the note value style used in the example above uses an equivalence 1 beam level = minim). A future extension might allow to overcome the style default on a per-score basis, but not initially.
Work is going on, but comments and suggestions are welcome.
Some notes:
1) It is not my plan to implement any contextual management of beams: "Beam start" generates a simple stem and "Beam middle" generates a stem with the appropriate numbers of beams, regardless of what come before and after; it will be the user responsibility to built meaningful sequences.
2) The current plan is not to support "broken beams", which as far as I know do not occur in literature. Advices are welcome.
3) The current initial implementation gives 'for free' the possibility to generate value symbols at points where none of the current symbol repetition settings would apply.
Comments
Wow, superb rendering that this image :)
![dream.jpg]( "dream.jpg")
Your comments and questions are a bit too technical for me presently (sorry, I need to read x times!), but you have all my warm encouragements for this work.
The addition of beams as stated above is, in my view, a good advance, as these are extremely common in original lute scores of all kinds: Italian, French, and German, and from all time periods through at least the early 17th C. I find these beams serve to clarify the rhythmic structure and thus make the music easier to read.
As to correspondence with mensural note values, I believe these were fairly arbitrary at the time, based mainly on convenience. a | is sometimes a minim, sometimes a semibreve. This is only an issue when, as in lute songs, there is a mensural staff to go along with the tab staff. It would be convenient to be able to set the correspondence in some way in a staff (e.g. | = minim or | = semibreve, etc.). Sometimes, a minim or semibreve is given by a flag with a *left-sided* tick, like
/|
|
I, personally, find it most convenient to the latter symbol as a semibreve and | as a minim,
|\
|
as a crotchet, etc. fronimo and django, probably the most commonly used tabsetting programs, do this, though in actual historical scores, either one *or* the other is used, not both. Nevertheless, this is, as I said, most convenient. Rarely, I have seen | as a minim, a dot above the staff as a semibreve, and 2 dots above the staff as a breve.
Next challenge: to have a rest, commonly notated as a rhythm flag with no underlying note or symbol.
--Sarge
In reply to The addition of beams as by sgerbode
Hi Sarge,
Not being a lute player myself, I only have a limited knowledge of the lute repertory; tablatures exist also for my instrument (viola da gamba), but they are not very common and limited only to some areas.
That said, it seems to me that, roughly speaking, the systems of value symbols used in historical sources can be grouped in two main kinds:
1) the one appearing in the example above (and which I have called 'Italian' in MuseScore, because -- as far as I have seen -- it the one almost exclusively used in Italian-style tablature prints, though it is not limited to them only) and
2) the systems using 'real' note symbols (or parts of them, or some 'real' notes and some partial symbols, which I have called "French" in MuseScore, just in opposition to "Italian").
In all the sources I have seen which use a system of the group 1) and for which a mensural correspondence can be established with certainty, '|\' is a minim, '|\\' is a crochet and so on. I have met this correspondence in English prints, in Italian prints, in French prints... If there are evidences for different correspondences, I am eager to learn about them.
Then, there is the issue of the value reduction in modern editions (by half, by four, ...) with respect to the original values, which may force a difference correspondence. Of course, it would be nice to support this too; however, in my personal priority list, supporting 'philological' renditions comes before. So, my plan is to support one correspondence per value symbol style first; more configurability (for instance, per score) might come in the future.
"Next challenge: to have a rest, commonly notated as a rhythm flag with no underlying note or symbol.": in "Advanced Staff Style Properties" | "Note Values", try checking the "Show rests" check box... (<g>)
In reply to Hi Sarge, Not being a lute by Miwarre
Hi, Miwarre.
I'm a bit confused, because the tabs you give in the above examples are French tab, not Italian. Maybe I missed out on some earlier examples. I find the beaming style in original facsimiles to be pretty independent of the style of tab. So there are many examples both of beamed and of unbeamed flags in all three styles (French, Italian, and German). It is thus advantageous to have a single command to do a "beam all flags" and one to do "unbeam all flags".
One also sees in original tab facsimiles the same piece rendered in different settings with differing note values and differing barring. And, as you say, there are modern renderings with reduced note values where the correspondence between mensural and tab can be pretty arbitrary, so at some point this issue will have to be addressed.
Thanks for all your good work!
--Sarge
In reply to Hi, Miwarre. I'm a bit by sgerbode
Ok, as far as fret marks are concerned, there are 'Italian' tablatures (numbers, bottom up strings, ...) and 'French' tablatures (letters, top-down strings, ...) and we all agree on this (let's leave German tablatures aside...).
But as far as mensural value symbols are concerned, also it is possible to discern two main groups (with a greater variability perhaps): the 'sticky' systems (if you prefer to avoid the label "Italian") using '|', '|\', '|\\', ... and the 'real note' systems, using 'regular' note symbols (in some cases, parts of them). The Dowland example above employs a 'sticky' system; your Corkine example employs a regular note system.
In the 'sticky' systems I have seen, the equivalence '|\' = minim seems largely prevalent (if not universal; probably in tablatures there is nothing of universal!); in the 'regular note' systems, each note symbol has its own 'usual' value.
So, in your example, I do not see a '|\' = crochet equivalence, as I do not find any 'sticky' symbol. I see minim shapes which count as minims, crochet shapes which count as crochets and so on.
Currently, MuseScore (the last released version) includes three styles of mensural symbols: one 'sticky' style (to be found under the label "Italian") and two "regular note" styles (under the labels "Modern" and "French").
The glyphs of the first are encoded for the '|\' = minim correspondence and then, with it, the implementation of this "beaming grid" proposal will use single beam for minims, double beams for crochets and so on.
OTOH, the glyphs of the latter two are encoded for the 'nominal' correspondence (a minim shape = a minim value) and then the beaming will use single beams for quavers, double beams for semiquavers and so on (as 'regular notes' do). All will be hard-coded in the style definitions. The possibility to 'shift' this correspondence up or down might come in the future (but I would hold my breath in this...), the hard-coded values becoming (customizable) defaults.
Does this clarify my plan somehow?
Anyway, thanks for your observations which help me in focusing my plans!
Maurizio
EDIT: I forgot to reply to a point. Removing all beaming will be easy: select all the relevant notes and double click the "AUTO" beam setting. Adding all the beaming is less easy, as it is not self-evident which values should be beamed and which should not. Or you had something different in mind?
In reply to Ok, as far as fret marks are by Miwarre
Sorry. After I had sent my "Corkine" example, I found it was a bad one. I tried to edit it out, but evidently the original version went through.
A thought on "restoring" beams in tab: Yes, museScore will have no way of knowing exactly how the beams are to be applied. But one approach is to have a default behavior to a command to "beam notes", and then to have a way of manually beaming or unbeaming individual notes to catch the the ones that don't fit the default. In 3/4, by default, the program should beam quavers in groups of 2, semiquavers in groups of 4. In 6/8, quavers would be in 2 groups of 3 per bar, etc. The default beaming should fit the time signature of the piece. Note that in "classic" tab, as opposed to mensural notation, one cannot beam notes of unequal value. Thus one cannot beam a quaver with 2 semiquavers.
--Sarge
In reply to Sorry. After I had sent my by sgerbode
In principle, it would be possible, but not easy: beaming also depends on the "beaming level" discussed above (which value has no beam, which has one beam, which has two, etc.) and time signatures, applied to Renaissance and early Baroque pieces, are a rather thorny matter.
So, I would leave this to a next step (or perhaps to a plug-in?).
Dowland's Galiard completed:
NOT FOUND: 1
and a detail of measure 7 enlarged:
NOT FOUND: 2
(I was not able to hide the values and the measure number above the extra measure for the instrument tuning, but this is another topic).
I feel that the graphics is defined enough: comment anyone?. Now, back to some structural issues still lurking (like re-drawing lagging behind).
PR pushed to github: https://github.com/musescore/MuseScore/pull/2235
Tests, comments, suggestions are welcome!
In reply to PR pushed to github: by Miwarre
Oh yes, Miwarre, the tests are very welcome! I am so impatient to try this new feature for the input of the fabulous English Renaissance repertoire, inter alia :)
But I have to wait the merger of this PR. I do not know how to build a Nigthly.
Ahrrr, poor me...! :(
In reply to Oh yes, Miwarre, the tests by cadiz1
A few thoughts:
1. Beaming in tab facsimiles, when present, always starts at the |\\ level (crotchets) and not minims, semibreves, etc.
2. Rhythm flags of unequal value are never beamed together.
3. Time signature symbols in early music in general and in lute tab in particular are variable in meaning and idiosyncratic. I personally only use modern time signatures, as these are specific in meaning and more comprehensible to modern players. That makes the task of beaming easier.
I see little point in trying to duplicate exactly the early music notations in modern editions, as someone who wants to use these (a minority with antiquarian tastes) now has decent access to the original via facsimiles. Part of the point of encoding a modern edition is to make the music more accessible to modern players -- and to correct the many errors present in the originals.
--Sarge
In reply to A few thoughts: 1. Beaming in by sgerbode
Yes, there might be reasonable short-cuts, however the possibility of an 'automatic beamer' for this kind of scores remains complex (for instance, does it apply only to same symbol repeat setting at "Always" or also at "New measure", "New system" or "Never"?).
Your position about time signature is of course sensible and shared by many others; I personally try to always keep the original form, as early time signatures -- even once prolations had run out of use -- may combine time and tempo hints or (potentially) reveal habits or stylistic / geographic implications; so I prefer to choose a sensible (hopefully!) bar lining, hinting at the (modern) time signature concept, and keep the original form (of course, however represented, the underlying time signature in MuseScore does always follow the modern concept).
I do not feel this to be antiquarian or to forbid access to modern players: anybody interested in these genres, after a few pieces, will get the hang of it. Or at least, will be encouraged to make his own decisions (even wrong), rather than relying in mines (which can be equally wrong!).
This applies to most aspects of old score re-edition and I personally see a big point in duplicating most aspects of original prints; coloratio and ligaturæ are hard to achieve in most modern general-purpose music notation programmes, so I can stand replacing them with the modern values bracketed by the relevant symbols. Other aspects can be achieved with little effort and for me it makes sense to keep them; for instance, the usage of accidentals or the beaming (in late XVII c. prints, once moveable types have been replaced by engraving): by careful use of editorially marked accidentals, it is possible to give a text readable with the modern conventions, but at the same time faithful to the original....
Even under this perspective, re-edited scores have solid advantages over fac-similes: correction of errors, as you said, but also score layout (instead of separate part-books) and measure indication and numbering (which makes studying and rehearsing much less cumbersome), use of more used clefs (once the original clef is related in the incipit) and, last but not least for aging eyes like mines, the clarity of modern engraving and printing technologies.
Of course, both positions are worth, the important is that the programme allows both as far as possible.
In reply to Oh yes, Miwarre, the tests by cadiz1
As to that, here is a Nightly build for Windows (based on 0bc5ff562 ) with Maurizio's PR:
https://drive.google.com/file/d/0BxjayMZiuupOWFFXcE5SMnhLb2c/view?usp=s…
Ciao,
ABL
In reply to As to that, here is a Nightly by ABL
Thanks so much Antonio. Very appreciated -;)
For now, I fumble a bit! More time tomorrow to test.
![king .jpg]( "king .jpg")
But already, the result of the photo below is mine :)
@Miwarre: Can you please check my configuration on the attached file, if I did not make any mistakes: King Denmark test.mscz
- In particular, I had to choose a 6/4 time signature (and put the '3' Appearance, in the Time Signature Properties) to receive the good flags. Correct?
- Second thing: to achieve this (as on second measure from Dowland's Galliard):
![c troisième étape (1).jpg]( "c troisième étape (1).jpg")
![aquatre.jpg]( "aquatre.jpg")
![c troisième étape (2).jpg]( "c troisième étape (2).jpg")
![c troisième étape (1).jpg]( "c troisième étape (1).jpg")
The start point is this:
Then double-click on Start Beam to receive:
And then select the second note (double-click on Middle Beam) -> select the third note (ditto) -> select the fourth note (ditto) to get the wished result:
Is it this? Or has there a more faster way?
For instance, by selecting eg the first and fourth notes, I do not get the expected result.
In reply to Thanks so much Antonio. Very by cadiz1
I improved my way of working (need still practice). First, a 3/2 timesig instead 6/4 is better!
![resultat.jpg]( "resultat.jpg")
![aquatre.jpg]( "aquatre.jpg")
![c troisième étape (2).jpg]( "c troisième étape (2).jpg")
![blue rectangle.jpg]( "blue rectangle.jpg")
Then for beaming, to obtain this eg.
Start point is as below:
Then, selection first note -> double click on Start Beam (first icone, in Beams properties palette). Result:
Then, selection of three following notes:
->double-click on Middle Beam (second icone, Beams properties). Result, as first image.
I'll go on another thread for other possible questions, but I think I understood the essence now.
In reply to Thanks so much Antonio. Very by cadiz1
Well, as you did in your second tests, in my transcription reproduced above I used 3/2 (mathematically equivalent to 6/4, if not musically); the point is that the '|\' glyph is encoded to the minim value (and it is so since the beginning of MuseScore TAB's, nothing new here), as this is the equivalence shown by all contemporary sources I could see in which the mensural values can be established with certainty.
About speeding up the process, you already found the major improvement possible: selecting notes (or chords) in groups. As a general concept, I tried not to assume (almost) anything: any chord can be given any beaming and it obeys it independently of anything before or after: it is the responsibility of the user to arrive at sensible sequences. Ideally, this should allow to reproduce all the sequences occurring in sources (among many other...).
And, yes, many thanks and kudos to Antonio for providing a suitable nightly!
In reply to Well, as you did in your by Miwarre
I continue my tests. Everything is going well so far.
But I am fear of forgetting something: I do not understand on this page: https://github.com/musescore/MuseScore/pull/2235, in the last paragraph "Also", the first two points: "Implements to possibility to force ..." and "Implements the 'no stem'.. .
If it is useful for better understanding, could you expand a bit with an example of using? If too 'technical', no matter.
- Other thoughts:
1) When I first tried this function, I naively believed that this matter of beaming worked in note entry mode!
For example: I press the Middle beam symbol in the palette, and the beaming is displayed automatically (as for a standard staff). Then I return to Auto or Start Beam (maybe via a shorcut) to continue. I understood a few minutes after that these operations of beaming should be effected after, outside the input mode!
2) For correspondence "shape / value", and while I understand this choice, it goes against my habits.
![deux parties.jpg]( "deux parties.jpg")
My use is almost always to display the Standard staff and Tab staff linked (for historical Tabs.) I keep this file with these two linked staves. Like this:
Then I keep the single Tab staff, because it's visually nice :), inter alia advantages... And finally, and as importantly, I keep the standard staff to make an adaptation for guitar. It's a way for me to discover and share this remarkable repertoire.
However, in this case, with a 3/2 timesig, I get this:
![blanches.jpg]( "blanches.jpg")
While my wish is to get this (as my habits, and common in the contemporary publishing):
![result guitare.jpg]( "result guitare.jpg")
And so, in this case of the English tabs, I must make a choice.
I should be able to survive. I hope!
And there's only a few days, the way to display the English tabs seemed to be a distant project. So, we are in great progress! :)
In reply to I continue my tests. by cadiz1
Some news of this... new feature. After testing during more a week and after entering a dozen of scores, all works very fine here. I made several operations, inter alia with copy/paste, linked staves, and toggle between differents styles and configurations: I have not seen something unexpected, or issue, not even the shadow of one.
As I said, there a few weeks ago, this feature seemed to be a sweet dream …So, so much happy :)
And kudos to Miwarre to have succeed this.
In same time, the feature is depending a lot with double-clicks, and can request a consequent work of beaming editing, as entry work surplus, according the piece (eg with many 'diminutions', short note values)
Two shortcuts (for “Start Beam” and another for “Middle Beam” ) could reduce this part of double-clicking. All operations of notes selection will be made with mouse + those for beaming with shortcuts. But knowing that the shortcuts are a rare species, I do not make myself any illusions about this.
Concerning the correspondence with mensural note values, currently: | is assigned to the semibrevis, |\ to minima, and so on. As discussed herein : https://musescore.org/en/node/81051#comment-358386, the use could vary, and so the ability to overcome this style default would be great, ie for this other correspondence: | as minima, |\ as crotchet, etc.
![duration values.jpg]( "duration values.jpg")
![mesure à trois temps.jpg]( "mesure à trois temps.jpg")
This is not a whim, it is only because an important part of my work is to adapt, arrange early music for guitar.
For now, I get this:
While this result would be preferable, because it's became the standard/usual notation in contemporary publications.
In reply to Some news of this... new by cadiz1
Thanks to cadiz1 for the positive comments!! A few notes:
1. Short-cuts: actions for beam modes already exist, they simply have no short-cut defined in the default setup:
NOT FOUND: 1
Try defining some short-cuts of your own for them and they will (should?) work. If you find some short-cuts you think useful and without conflicts with already existing ones, let us know: it might make sense to add them in the default settings.
2. Linked beam mode: this is a question. Did you notice any problem from the fact that beam mode is copied across linked staves? To put it clearer: assuming it would be possible to have the TAB you quote right above linked to the "preferable result" you give for standard notation, it would not be possible (at the moment) to have the four short notes in the second measure beamed by four in one staff and beamed by 2 + 2 in the other, as your example show: they would have the same beaming, decided by the last beaming modification on either staff. Do you have any comment on this?
Now, some points not directly related with the "grid" beaming.
3a. Note values: we already discussed this at some length (incidentally: please note that this does not depend on this "beam grid" feature, but on the encoding of the font glyphs; even with the non-gridded values, the correspondence would be the same).
I still have to find examples of Renaissance / Baroque sources in which the correspondence between the 'sticky' note values and the mensural values are demonstrably different from the current setup. Of course, I cannot be sure they do not exist, but they have to be quite rare or idiosyncratic; anyway, examples are welcome.
Now, as we all know, the practice exists to halve (and sometime to divide by four) the values when transcribing early music to 'modern' notation; it is a debatable -- and debated -- practice; I believe the more recent practice is to keep the original values, but that practice is for sure widely used. At the same time, tabulatures are not halved, but keep the original values.
What you ask for is the possibility to have the tab staff with a time signature of 3/2 (as, I am rather sure, it was in the original) corresponding to a standard staff with a time signature of 3/4 (and values halved). This is not possible at the moment in MuseScore; at least, I could not find a way (it has the notion of staff time stretch, but I could not find any way to use it).
3b. Basses: I note another significant difference between the result you get with linked staves and the "preferable result": basses are one octave higher in 'modern' notation (presumably because the guitar does not have that low D). As you can easily imagine, there is no way that a musical notation programme (more, a general purpose notation programme) can 'improvise' this kind of cross-instrument adaptation.
These two points (3a. and 3b.) let me believe we are hitting another example of the fact that tabulature and standard notation are two structurally different notation systems and transcoding from one to the other is not really possible, unless for the most simplistic cases: a 'translation' is required but, as we all know, automatic translation is still to come (Google Translate docet).
So, I doubt it will be ever possible to have a completely satisfying rendition of such a translation by using linked staves: independent staves (and in some cases, separate scores) will be required, no matter how 'intelligent' we attempt to make the programme (and programmes are not intelligent at all!).
In reply to Thanks to cadiz1 for the by Miwarre
1. Shorcuts:
Yes, saw this morning and assigned shortcuts - on the top row of the keypad - for the Start Beam ("-") and Middle Beam (*)
I had to move elsewhere the second one that I had assigned to something else!
I do not know if it might make sense to add them in the default settings. Because these shortcuts, mine, may be used more frequently on other keyboards? Don't know. To see.
In any case, I confirm, it works well: navigation with the arrows for the notes selection, and snap the Start / Middle Beams with shortcuts. Much more comfortable. Exit the clicks and double-clicks (except for the Auto Beam, to correct mistakes ... unless we find a third shortcut without conflict!)
The only thing you lose is the ability to select for instance three notes, and to made the beaming action with only one double-click on Middle Beam. The shortcut fails with this. We must make note for note. However, one can mix the two methods depending on the context.
2. Linked beam mode.
![2 beaming.jpg]( "2 beaming.jpg")
![3 result expected.jpg]( "3 result expected.jpg")
A first point not clear yet. I do not quite see where you're going, or far.
For now, with linked staves, and by typing the notes in the tab staff, I receive this :
After the beaming operation, I get this expected result.
What would intend to do otherwise?
3a. Notes values
« note that this does not depend on this "beam grid" feature, but on the encoding of the font glyphs; even with the non-gridded values, the correspondence would be the same). «
This is a second point that is not clear yet in my mind, sorry. Maybe I forget something, but I don't get the same result. I'll dig this question for it later if necessary.
« This is not possible at the moment in MuseScore; at least, I could not find a way (it has the notion of staff time stretch, but I could not find any way to use it). «
Pity. But/and maybe related to my previous reply.
3b Basses. :
“I note another significant difference between the result you get with linked staves and the "preferable result": basses are one octave higher in 'modern' notation (presumably because the guitar does not have that low D) “
Indeed. But this has never been any request, and I would never want to! All is well and as expected here. This is my arranger job to transpose the piece if necessary, and to reconfigure the bass line based on the inevitable constraints due to a change of instrument: eg 8 strings/or 13 strings vs. 6 strings!
And this is easier as one might think :)
In reply to 1. Shorcuts: Yes, saw this by cadiz1
I don't think I found the nightly build that includes the new shortcuts, but they sound like a great idea.
I agree that beaming in tab should parallel beaming in mensural music, with the possible exception that in historical tab one does not beam notes of unequal value.
On auto beaming: I don't believe this is implemented yet, right? When it is, I believe that it should apply to an entire system. It would seem weird to have one beaming style in one measure and another style in the next. But if this does happen, it could in any case be adjusted manually.
On folding of notes: I think if a transposed or imported piece has notes that fall outside of an instrument's range, it should generate an error message rather than automatically folding these notes. Folding up bass notes is an editorial task that may require some thought. As Cadiz1 says, however, this is not that difficult a task.
I am just beginning to familiarize myself with MuseScore: can one automatically generate a tab version of a given mensural line?
In reply to I don't think I found the by sgerbode
- On Auto Beaming/Auto Beam, I do not know what idea you have in mind, but I suspect that there is probably misunderstanding. This has nothing to do with the feature in standard notation. Miwarre correct me if I am unclear.
For Tabs, it is the default style of this feature, ie in: Advanced style properties / Notes values / Shown as: Note Symbols / Repeat: Always / Tab Italian Font.
I thought a moment, a brief moment, that this feature might work in note entry mode. This may be the same source of misunderstanding? Unless I am mistaken, I do not think it's planned or possible?
- On "folding of notes", this already exists. No error message, simply displaying of colored notes to indicate that they are outside the usual pitch range of the instrument. This is an option that can be turned off (this is what I do, I know well my instrument!) in: Preferences / Note input.
- Finally, "one can automatically generate a tab release of a Given mensural line?"
Yes, of course.
In the Instruments dialog box (shortcut "I"), you simply have to change the staff type (in the right column, with a drop liste)
In reply to 1. Shorcuts: Yes, saw this by cadiz1
2. Linked beam mode
"A first point not clear yet.": I looked at the example you posted here above , where you said that the following tab should have this "preferred result":
NOT FOUND: 1
It is not possible to have different beaming in linked staves, as it appears in your examples, where the tab has four notes beamed together and the standard staff has two beam groups of two notes each; when the user sets the beaming mode of the notes of one staff, the other staff automatically receives the same beaming; if this is expected, ok nice; it was not what your examples hinted at, though.
3a. Notes values
"This is a second point that is not clear: the correspondence '|' = semibrevis, '|\' = minima, '|\\' = semiminima, etc. is built-in into the font glyph mapping (as in standard notation, 'white' note head = half note, 'black' note head = quarter, 'black + '|\' = eighth, etc. is built-in into the code) and it does not depend on using or not using the "grid beam" feature. The request to have this mapping made variable amounts to having the possibility to mix staves with different time signatures, something that MuseScore does not currently support, as far as I know, and which does not seem a simple thing to add.
3b. Basses: Again my observation was about linked staves. With linked staves, basses cannot be 'folded' independently on one staff; if you do it, they would be folded in the other staff as well. So, I do not think it would be possible to have in any foreseeable future that tabulature and that preferred standard staff rendition (same post linked to above) by using linked staves: independent staves with ad hoc adjustments on either side will be necessary.
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Browsing previous posts again, I noticed I still owe you an explanation about the "stem / no-stem" features in that pull request. It is rather simple; the appearance of value symbols is governed by a simple algorithm: if the chord duration value is different from the value of the previous chord, a value symbol is drawn; if the value does not change, the same symbol is repeated or not according to the "Repeat" setting of TAB config. All is simple, automatic and mechanic.
I expect there might be exceptions to this simplicity: the occasional symbol the user wants to be repeated even outside of the "Repeat" setting, or the occasional chord which would normally receive a symbol but which the user prefers not to have.
The first (force a symbol not automatically present) can be obtained by setting the chord beam mode to anything which does not have a specific TAB meaning (i.e. any value except "Auto", "Start" or "Middle"; typically "No beam"). The second (skipping a symbol which would be otherwise generated) can be achieved by checking the "Stemless" property in the chord Inspector. Maybe not very common, but potentially useful, I believe (as we all know, tabulatures are rich in exceptions and particular cases).