Suggested clarification of "SoundFonts" and "GM"
MuseScore's built-in synthesizer is designed to use collections of instrument sounds in an industry-standard file format known as SoundFonts. Each of the instruments in your score can be associated with one instrument sound in the SoundFont file that you currently have selected. (You can change those assignments at any time using the Mixer window.)
As you create your score, perhaps with the intent of sending the files to other people or of playing them on computers other than your own, you will of course want your music to sound right anywhere, even on a computer with a different SoundFont installed. This is why we recommend using SoundFonts that conform to the General MIDI (GM) convention. This is usually indicated by the letters -GM- somewhere in the file name.
The computer refers to the instrument sounds in a SoundFont by an instrument number ("channel number"), not by name. Therefore, all General MIDI files abide by the same agreed-upon conventions as to which ranges of instrument-numbers refer to which types of instruments. While the sounds corresponding to each instrument number are not the same, they will always be acceptably similar. (In other words, it won't sound like complete nonsense.) Physical instruments and outboard musical equipment can also typically recognize the General MIDI instrument-number assignments.
Also note: Many SoundFont collections contain many different files, such as those with GS in their name. While these also are SoundFonts, the arrangement of sounds within these files doesn't conform to the General MIDI specification. Thus, anyone who was playing back your score would be required to know exactly what file you had used, in order to achieve sensible results.
Comments
That's quite clear.
I question the word "file" in your last sentence. It is not clear that you mean (I think) "soundfont file".
Regards.
In reply to Quite clear by xavierjazz
Yes. That's exactly what I meant. "Well spotted..."
I chose that word because, had I used the word "SoundFont" in the context that I had just created, it has become a little ambiguous. Am I referring to "the collection," or to "a particular file?"
(Answer: "to a particular file.")
Actually, the person would need to know exactly what [version of what...] collection you'd picked, and exactly what file within that collection, just to achieve a sound that is even vaguely comparable to what you had intended. (The person might laugh uproariously upon hearing "Ah-oo-ga!" from a klaxon where you intended to place a delicate piano, but it will most surely be a joke made at your expense.) If the person intends to use physical hardware, he's going to have to "re-map" your instrument number assignments just to achieve an initial, sensible, "okay, let's have a listen..." playback of your material. Not what you want ...
Further clarifications welcome.
Per your suggestion, I added a sentence to the SoundFont page about why General MIDI is important:
"If you use a SoundFont that does not conform to the General MIDI standard then others may not hear the correct instruments when you share the score or save as MIDI. "
The page also links to the Wikipedia description of General MIDI for a more detailed explanation.
I suspect that it will be less common for users to deal with SoundFonts in the future since the upcoming version 0.9.6 will include a GM SoundFont by default.
In reply to Per your suggestion, I added by David Bolton
That's a great solution.
Regards.