Re: Midi entry (was: Changing and playing a different instrument in MIDI)

[Richard Shann]

On Fri, 2016-07-22 at 17:50 +0200, David Kastrup wrote:
> Mojca Miklavec <address@hidden> writes:
> 
> > Off-topic:
> >
> > That said, I wouldn't mind suggestions for some good OpenSource (GUI)
> > MIDI editors. I have a bunch of weird MIDI files that I would like to
> > turn into scores. They sound OK, but I'm not exactly sure if they were
> > just obfuscated on purpose or if they are recordings of "human
> > players" and thus the timings are some horrible (i)rational numbers.
> 
> midi2ly is unsuitable for quantizing human play.  It's really just a
> software-produced Midi reimporter.
> 
> "rumor" is rumored to be a bit better but its website is gone.  It still
> can be installed in Debian and has Info documentation.


Following on from the last time this topic came up I built rumor and ran
it and looked at its source code. The good side is it creates LilyPond
syntax directly, but the down side is that the "u" in Rumor stands for
"Unintelligent" and, indeed I can't believe it will save you time. This
got me thinking that there is quite a lot of software available in these
repositories, so I started digging around and came across FANN a neural
network library. I've created a neural network that classifies each note
in a MIDI track by considering the its timing and that of the previous
and following note.
This is just at the toy stage - it only classifies whole,1/2,1/4 and
1/8th notes with no support for dotted notes, or rests following notes
let alone tuplets. So far it has 500-odd shortish training patterns and
works fairly often. But I'm doubtful is this the right approach - it
seems something I think you (David) mentioned before on this topic -
Hidden Markov Models - would be a better fit to the problem. But sadly
there doesn't appear to be anything approachable-looking in the Debian
repository for making a start on that.
> 
> If you do Emacs, I have code for entering stuff on accordion via Midi
> (without duration, but picking apart the channels for treble and chord
> side and basses and being able to recognize chords and tell them apart
> from legato play).  Emacs' LilyPond mode itself is woefully underpowered
> and in need of some love, however, so this makes mostly sense when being
> able to use Emacs is a reward rather than a penance for you in the first
> place.
> 
> Denemo (which exports to LilyPond) has some Midi entry modes IIRC, there
> might be some Youtube tutorials.

Denemo's tutorials are mostly on vimeo.com. There are some for the MIDI
entry, but again they won't be much use unless you know what the right
rhythmic notation is. (What it *does* do is to let you visualize a MIDI
track as notes dotted along a click-track, so you can make shrewd
guesses as to what the note durations are, stepping through them one at
a time - Denemo makes suggestions which you can just accept if they are
ok). But this is a million miles from being able to give a
performance-generated MIDI file to a program and it generates a
plausible score - you are going through the whole thing note by note.

Richard