On the MuseScore element <duration>

• Dec 15, 2020 - 02:32

As with much of the MusicXML language, it is not easy to discern from the MusicXML "specification" and the supporting documentation just what is the "intent" regarding the element duration. And I have not had the benefit of any conversation with such experts as Michael Good, the godfather, and current principal keeper, of the language.

But from extensive contemplation I conclude that, for practical purposes, the "intent" is:

• The element duration dictates, in numeric form, the time value ("quarter", "eighth", etc.) of the note).

• If present (it is optional), the element type also dictates (in this care in enumerative textual form) the time value of the note. That is, properly the two elements should dictate the same time value.

Of course, in the latter situation (certainly the most common today), this is redundant. But I conclude that this is the result of the evolution of the language.

Now, what if the value of duration is not consistent with the value of type? Well, they should be consistent.

I'm sure this is a somewhat discomforting conclusion.

As of version 3.5.2, it seems that MuseScore's reaction to duration and type in a MusicXML note element is this; I presume here that both those elements are present:

• The value of type dictates the time value ("quarter", "half", etc.) of the reconstructed note.

• The value of duration dictates the allotment of musical time to the note. This in effect means how much musical time there is from the start of the "era" of one note to the start of the "era" of the next note.

• The sounding eras of the notes begin at the start of the note's era, and the duration is as indicated by the note's time value.

If in a particular case, the values of duration are not consistent with the values of type:

• Usually MuseScore will give an error message.

• If we proceed, an odd structure of the measure(s) is created. (I will not describe that in detail; the whole story is rather complicated, and a bit ugly.)

It is hard to tell what sort of plan this behavior is meant to implement. In any case, a sensible result only obtains if, for each note, the values of type and duration are consistent.

I recommend that the behavior of MuseScore upon the import of a MusicXML file be made as follows with regard to this aspect of note elements:

• If there is no type element, the time value of the note should be as implied by the value of duration.

• If there is a type element, the time value of the note should be made to follow that, and the duration element should be ignored. [Yes, that is shocking!]

• The musical time allocated to a note should be equal to its time value.

• The base play era should begin at the start of the note era and have the same duration as implied by the note time value.

• If there is an attack attribute and/or a release attribute for the note element, they should be honored to shift the start time of the play era and/or the end time of the play era, respectively.

I will discuss later my recommendations regarding the generation of MusicXML code.

If the above were adopted, would that lead to the general ability to interchange scores from other notation programs to MuseScore and end up with a score that would play the same as it did in its program of birth? Not unless other programs did what I recommend.

Would there be a different scheme that MuseScore could adopt that would allow such interchange on a broad basis? No. Unless we limit ourselves to scores in which all notes are expected to start at the nominal time and play for "100% of face value", in which case MuseScore can receive those successfully now.

Just sayin'

Best regards, and stay safe.

Doug


Comments

Here is my complementary recommendation as to the encoding of the aspects described in my prior note into MusicXML code:

• For each note, the time value should be described in a type element and in a duration element.

• If for a note the established start and/or end play times differ from the start and end of the note era, these offsets should be described by an attack and/or release attribute, respectively.

Best regards,

Doug

In reply to by Doug Kerr

Upon further reflection, I suggest that the algorithm for the interpretation of an incoming MusicXML file be this, rather than as I had recommended earlier:

• If there is no type element for a note, the symbol for the note (its time value) should be as implied by the value of the duration element.

• If there is a type element, the symbol for the note (its time value) should be made to follow that.

• The musical duration of the note (the musical time until the next note is considered to start) should be the same as the time value implied by type.

• If there is neither an attack nor release attribute to the note element, the play duration should be as indicated by duration.

• If there is either an attack attribute and/or a release attribute for the note element, the "base" play duration should be the musical duration of the note, but with its play start time and/or play end time shifted as indicated by attack and/or release.

I believe that this form of the algorithm should give a high probability that MuseScore will be able to make something sensible out of the MusicXML files generated by a range of modern notation programs.

Certainly others here with more experience in this overall matter than I may recognize that my outlook is flawed.

Best regards, and stay safe.

Doug

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