Re: Support articulations, slurs and breaths in MIDI (issue 26470047)

[Keith OHara]

On Sat, 23 Nov 2013 08:31:17 -0800, Devon Schudy <address@hidden> wrote:

> Is “relative-volume” clearer? Also, should it have something like
> “perform” in its name (or “midi”, like the midi* context properties)
> to make it easy for users looking for a layout property to ignore it?

Adding 'midi-' would help.


> The trouble with calling it ‘velocity’ is that dynamics currently also
> set velocity rather than channel volume, which is why they can't
> change the volume in the middle of a note. (There's code for using the
> channel volume, but it's disabled, apparently because of bugs?) Also
> users might expect velocity to be an absolute MIDI velocity of 1 to
> 127 rather than something relative to the dynamic.

Using the word 'velocity' in the name of the property that affects the MIDI 
"note-on-velocity" should not cause confusion.   Adding 'relative-', or the doc-string 
you already have, or seeing how the property is used with accents, should prevent misunderstanding 
as the absolute "note-on-velocity".

In version 2.12, dynamics were implemented as channel volume.  The volume did 
not change in the middle of the note, however, because there was no system to 
generate a midi event in the middle of the note.

Sometimes two lines of music share a midi channel (if we need all 16 channels 
for different instruments) and Jan added an option to do that automatically.  
But then when left- and right-hands of piano, for example, shared a MIDI 
channel but had different dynamics, they would fight over the single volume 
setting.  Jan moved the dynamic implementation to note-on-velocity.

MIDI note-on-velocity is good for dynamics.  I think several midi players 
adjust the timbre based on that velocity.  Crescendos can still be implemented 
with the channel 'volume', or better the 'expression', if we add a mechanism to 
send a few control-change events through the crescendo.