Re: Mostly unisono multi-voice staff also merging whole notes together

[David Kastrup]

Knute Snortum <ksnortum@gmail.com> writes:

> On Sat, Sep 11, 2021 at 12:03 PM Hans Aikema <hans.aikema@aikebah.net> wrote:
>>
>> Hi all,
>>
>> In a score I have two parts (Alto I and II) that’s for most of the score 
>> unisono.
>>
>> In order to be able to also generate rehearsal midis by voice (with
>> the concerned voice highlighted by diminishing the volume of other
>> voices) I would like to retain the full individual voices.
>> This rules out
>> … << { \voiceOne … } \new Voice { \voiceTwo … } >> \oneVoice ...
>> pattern for temporal polyphonic music as it introduces the problem
>> that the two voices displayed in the staff are now split in a way
>> that would at least not allow me to create a rehearsal miditrack
>> with voice that takes its polyphony notes from the \voiceTwo section
>> highlighted.
>>
>> For easier readability of the unisono part however I would like
>> (visually more condensed) the whole notes to join up like all the
>> identically-headed-and-pitched stemmed notes do.
>>
>> So what I’m trying to achieve is the notation effects of
>> <<
>>     { \once\override NoteColumn.ignore-collision = ##t f'1 |
>> \once\override NoteColumn.ignore-collision = ##t f'1~ | f'1 | f'2(
>> g'4 a'4) } \\ { f'1 | f'1~ | f'4( e' d' c') | f'4( e' g' a') }
>> >>
>>
>> % rather than the fully proper from notational perspective default rendering
>> <<
>>     { f'1 | f'1~ | f'1 | f'2( g'4 a'4) } \\ { f'1 | f'1~ | f'4( e'
>> d' c') | f'4( e' g' a') }
>> >>
>>
>> % or the completely broken
>> <<
>>     \override NoteColumn.ignore-collision = ##t
>>     { f'1 | f'1~ | f'1 | f'2( g'4 a'4) } \\ { f'1 | f'1~ | f'4( e'
>> d' c') | f'4( e' g' a') }
>> >>
>>
>> without having to sift through the score looking for the colliding
>> whole notes in order to add a \once\override
>> NoteColumn.ignore-collision = ##t to them
>>
>> Wondering if there would be a good solution that I’m somehow overlooking
>>
>> kind regards,
>> Hans Aikema
>
> Well, I don't think you can avoid "sifting through the score",
> otherwise how would LilyPond know when you want to ignore collisions?
> But you can make it easier to do:
>
> %%%
> \version "2.22.1"
>
> ignoreCollision =
> #(define-music-function (bool) (boolean?)
>    #{
>      \override NoteColumn.ignore-collision = #bool
>    #})

Well, that's just

ignoreCollision = \override NoteColumn.ignore-collision = \etc

(admittedly the explicit function has better typechecking).

But when there is no expectation of actually using a variable expression
here ever, it might make more sense to define two separate commands
\ignoreCollision and \avoidCollision .

-- 
David Kastrup