Re: MIDI tick resolution

[Thomas Morley]

2018-03-20 2:49 GMT+01:00 Ivan Kuznetsov <address@hidden>:
> Gilberto Agostinho <address@hidden> wrote:
>>
>> Does anyone know if it possible to change the tick resolution of LilyPond's
>> MIDI output to a value other than the default 384? One reason for wanting
>> this change is due to the fact that 384 cannot be divided by 5 and so
>> quintuplets on a crotchet are not precise.
>
> No, they would not be precise but they would perceptually be
> exact enough.  Without knowing precisely how these midi clock
> values work, I would imagine that the five notes of a quintuplet
> in a MIDI file would have the following clock durations: 77 77 77 77 76.
>
> So what if four notes are of length 77 and one note is length 76?
> No one can hear the difference.

I tested two files

(1)
\score {
  {
    \time 2/4
    \tuplet 3/2 { c'8 8 8 8 8 8 }
  }
  \layout {}
  \midi {}
}

(2)
\score {
  {
    \time 2/4
    \tuplet 5/4 { c'8 8 8 8 8 }
  }
  \layout {}
  \midi {}
}

with the sequence

lilypond file.ly
mid2ly file.midi
lilypond file-midi.ly

The resulting file-midi.ly shows (only excerpts)
(1)
trackBchannelB = \relative c {
  c'4*128/384 c c c c c
  | % 2

}

Looks correct.

(2)
trackBchannelB = \relative c {
  c'4*153/384 c r4*1/384 c4*153/384 c r4*1/384 c4*153/384
}

Inserting rests here is surely not that nice.


So I'd say there are use-cases where the midi-tick has direct and
visible impact.

Cheers,
  Harm