Re: "Problematic" conversion from MIDI: c4*5, c1 (in 3/4 time) etc.

[David Wright]

On Fri 29 Jul 2016 at 14:29:57 (+0200), Mojca Miklavec wrote:
> I have a midi file that I wanted to convert into scores, but the
> scores simply don't look right.
> 
> While I have a real (relatively long) song in the MIDI, I believe that
> I can fully reproduce the problem with the following simple example:
> 
>     \score {
>       \new Voice = "melody" {
>         \set Staff.midiInstrument = "accordion"
>         \time 3/4
>         \relative c' {
>           c4 c c |
>           c1 d4 e |
>           f4*5 g4 |
>           f2.~ | % becomes f4*5
>           f2 e4 |
>           d4*3 | % becomes d2.
>           c4 c2~ | % becomes c1
>           c2
>         }
>       }
>       \midi { \tempo 4 = 160 }
>       \layout {}
>     }
> 
> (I picked accordion because one doesn't hear the duration with piano.)
> 
> The idea is to make midi from the above example first (lilypond
> test.ly), then convert midi to scores (midi2ly test.midi -o test2.ly)
> and typeset again (lilypond test2.ly).
> 
> 
> The resulting MIDI file sounds right, but the typesetting of it is
> very strange. I get just a single quarter note printed out rather than
> something that takes the duration of five times a quarter.
> 
> OK, that's probably expected when I consciously enter the above
> syntax, but not after conversion from a MIDI file.
> 
> I noticed that the whole idea of the asterisk operator is to print a
> single unit, but to prolong it in MIDI (or for other purposes). But
> there's a lot of inconsistency:
> - if I properly enter c2.~ c2, I get c4*5 from the midi conversion
> - if I properly enter c2~ c2, I get c1 which is "forbidden" inside 3/4
> - if I sloppily enter c4*3 which would typset in a very weird way, it
> comes out OK after the conversion as c2.
> 
> None of that makes any sense to me.
> 
> Sure I can manually fix the resulting plain text file, but I was
> wondering if there was really no better way to get this done properly
> and automatically.

In the absence of any output examples, I've attached what my system
produces from your source. Let us know what's incorrect. It looks to
me as if the original score is just what you (idiosyncratically) asked
for and the subsequent score has been "conventionalised" as one might
expect, because the midi performer has no way of representing your
odd notation.

(Ignore the addition of 00 to the midi filename; my lilypond command
postprocesses midi filenames to make them sort in the correct order.)

> (PS: please CC me in reply.)

This will happen automatically if you coerce you mail client into
including the header line:

 Reply-To: Mojca Miklavec <address@hidden>, address@hidden

Cheers,
David.

accord.ly
Description: Text document

accord.pdf
Description: Adobe PDF document

accord-00.midi
Description: MIDI audio

accord-00-midi.ly
Description: Text document

accord-00-midi.pdf
Description: Adobe PDF document