Re: Tight spacing in mensural notation (was: Re: Cadenza Senza Tempo Problem)

[Graham King]

> On 30 Oct 2019, at 21:41, Thomas Morley <address@hidden> wrote:
> 
> Am Mi., 30. Okt. 2019 um 19:44 Uhr schrieb Graham King
> <address@hidden>:
> 
>> Harm, I'm afraid I'm struggling with "#(ly:make-moment -3)"
>> 
>> The NR[2] shows four arguments to ly:make-moment, describes two of them, and 
>> then speaks a little obtusely of the _second_ argument to ly:make-moment 
>> being possibly negative, and I can't find any examples of a negative first 
>> (and only) argument online.  Most examples seem to use one argument, a 
>> positive rational, which I think I do understand.
>> 
>> Where does this syntax come from and what does it mean?
>> And why did you choose -3 ?
>> 
>> TIA
>> -- Graham
>> 
>> [2] 
>> http://lilypond.org/doc/v2.19/Documentation/notation/scheme-functions#index-ly_003amake_002dmoment
>> 
> 
> I intended to set common-shortest-duration to the length of a maxima,
> to get tight spacing, see IR
> (Similiar for base-shortest-duration, although this may be superfluous.)
> And I confused ly:make-moment and ly:make-duration :(
> 
> Though the duration-log of a maxima is -3, it's length is #<Mom 8>
> 
> See:
> \new MensuralStaff {
>  \compressFullBarRests
>  \applyMusic
>    #(lambda (mus)
>      (ly:music-set-property! mus 'duration (ly:make-duration -3))
>      (format #t "\n\tLength of music: ~a\n\tDuration of music: ~a"
>        (ly:music-length mus)
>        (ly:music-property mus 'duration))
>      mus)
>  b
> }
> 
> =>
> 
>    Length of music: #<Mom 8>
>    Duration of music: #<Duration log = -3 >
> 
> 
> So you better change in my proposal common-shortest-duration to:
> \override SpacingSpanner.common-shortest-duration = #(ly:make-moment 8)
> 
> Cheers,
>  Harm

Harm,
many thanks!  There I was, feeling inadequate in the face of what was, 
evidently, some seriously recondite lilypond-fu :)
I understand now.

BTW, your \applyMusic lambda function is a really neat way of explaining a lot 
in a few lines.

-- Graham