Re: \tripletFeel and \partial

[Malte Meyn]

Am 28.09.19 um 16:57 schrieb Malte Meyn:
> Hi list,
>
> \tripletFeel doesn’t automatically work with \partial. IIUC, 
> \tripletFeet x is just a shortcut for \applySwing x #'(2 1) and one can 
> use \applySwingWithOffset for music with upbeat. I tried that but cannot 
> get it to work properly. In the following code, left and right hand are 
> offset against each other. What am I (or LilyPond) doing wrong?
>
> I’m writing this to the bug list because it’s a 2.21 feature and at 
> least from the existing documentation I’m not able to produce correct 
> output which is a program or documentation bug ;)

It’s not a \partial or \applySwingWithOffset problem but a problem with 
how \applySwing works: It seems to take the notes in input order instead 
of sounding order/time. This means that you can have problems with 
unfold repeats and simultaneous music:

\version "2.21.0"
\include "swing.ly"

% bad: all c are long, all d short
\tripletFeel 8 {
  \repeat unfold 8 c'8
  \repeat unfold 8 d'8
}

% good (even number of notes)
\tripletFeel 8 {
  \repeat unfold 8 { c'8 d' }
}

% bad (odd number of notes):
% all c and e are long, all d short
\tripletFeel 8 {
  \repeat unfold 8 { c'8 d' e' }
}

% good (even number of notes in the first staff)
\tripletFeel 8 <<
  \new Staff { c'8 8 8 8 8 8 8 8 }
  \new Staff { d'8 8 8 8 8 8 8 8 }
>>

% bad (odd number of notes in the first staff):
% the swing is shifted in the second staff
\tripletFeel 8 <<
  \new Staff { c'8 8 8 8 8 8 8 8 8 }
  \new Staff { d'8 8 8 8 8 8 8 8 8 }
>>