Re: default midi velocity

[Martin Tarenskeen]

( My mail client is doing strange things ... this is another attempt to
send my message to the mailing list )

On Sat, Apr 04, 2009 at 08:05:17PM -0600, Carl D. Sorensen wrote:

> >> Anybody willing to take this on as a patch? It shouldn't be too
> >> hard, but I imagine it'll take some time grepping through the
> >> source files.
> >
> > If we agree that it's just a case of changing the default velocity,
> > then this is ideally suited to a Frog; on the other hand, it would be
> > great to be able to set the default volume in a \midi block, but that
> > looks much more complicated.
>
> I agree.
>
> But the specific request was to have the default value be mf, which I 
think
> should be a not-too-difficult task.

I patched my copy of lilypond and now have a default velocity of 90
instead of 127 (patch attached). I like this better.

But I also discovered things are a bit more complicated. In MIDI there
are 2 totally different ways to control dynamics:

1. Midi Control Change #7 ( Volume control )
2. Note On Velocity

Option 1 is used by lilypond to translate \pp \mf \cresendo etcetera.
Option 2 is set to 127 by default.

If I record playing my digital piano in a midi sequencer my dynamics are
written in midi velocity values. This sounds different than using
Control Change messages. I can explain this: If I hit the keys harder,
not only the volume changes but also the brightness of the tone. This is
accomplished using different sample layers and/or filters in a digital
piano to mimic the sound of a real piano. This effect is re-produced
using the Velocity values in the MIDI information.

A Midi Volume Control Change can be compared to turning the volume knob
or using the sliders on a mixing console: The volume changes, but
without the effect of the changing color of the sound.

That is why dynamics that are written in a MIDI file produced directly
by lilypond don't sound as natural and realistic as is possible using
MIDI. Imagine recording a piano player who plays everything ff, and the
recording engineer takes care of the dynamics using the sliders of the
mixing console. Not quite the real thing ;-)


Just some thoughts about MIDI.
Now let's make beautiful scores again using Lilypond.
If you want a default velocity of 90 instead of 127: patch attached.

--

Martin Tarenskeen

diff -ur lilypond-2.13.0.orig/lily/midi-item.cc 
lilypond-2.13.0/lily/midi-item.cc
--- lilypond-2.13.0.orig/lily/midi-item.cc      2009-04-05 21:11:25.000000000 
+0200
+++ lilypond-2.13.0/lily/midi-item.cc   2009-04-05 21:17:43.000000000 +0200
@@ -169,7 +169,8 @@
 Midi_note::Midi_note (Audio_note *a)
 {
   audio_ = a;
-  dynamic_byte_ = 0x7f;
+  dynamic_byte_ = 0x5a; 
+  // dynamic_byte_ = 0x7f;
 }