Re: Constructive Criticism and a Question

[Erik Sandberg]

On Thursday 28 December 2006 11:13, Brett Duncan wrote:
> Erik Sandberg wrote:
> > On Monday 25 December 2006 06:32, David Fedoruk wrote:
> >> Hello:
> >>
> >> I've been watching this discussion or debate. There are two ways to
> >> look at this problem. The first is from a programmer's point of view
> >> where the programmer is experienced with some computer languages,
> >> these days its upper level languages more and more. For these people,
> >> lilypond typesetting code feels comfortable when it is syntactically
> >> correct and when it makes sense in either computer or mathematical
> >> terms. A mathematical algorithm is what they are used to seeing.
> >>
> >> The other group has less mathematical knowledge, very little (very
> >> little compared to a programmer working on a major project like
> >> Lilypond) programming knowledge or experience. In all likelihood the
> >> only thing that connects these people is the printed musical score.
> >>
> >> At least in part I think these points have already been made. The
> >> question that occurs to me as a novice Lilypond user  (and one who
> >> jumps in the deep end with complex scores!)  is this: How will you
> >> deal with other types of prolongation or compression of notes into one
> >> or more beats or where the composers intentions are clear but they are
> >> not immediately mathematically correct?
> >>
> >> The example below is a single bar from a Beethoven Piano Sonata (Opus
> >> 31 number 3, 1st mvt. bar 53) in which two more out of the ordinary
> >> examples occur next to each other. You will excuse any mistakes in
> >> coding here, this doesn't render as it should.
> >>
> >>     upper = \relative c'' {
> >>         \clef treble
> >>         \key ef \major
> >>         \time 3
> >>
> >>    bf16[d f ef] \times 5/4 d16[ ef f g a] bf32[bf a c bf d c bf a g c g
> >> ef]
> >>
> >> }
> >>
> >> You can see how there are three beams, one for the notes in eaech
> >> beat. The first and second beat are quite clear, but the third one has
> >> eluded me as yet. The score has 12 thirty-second notes beamed together
> >> with  "12" below the note heads.
> >>
> >> The printed score is clear to the performer. The Lilypond code I
> >> suspect is far more complex. The only way that 12 thirty-second notes
> >> will fit into one beat is if they are triplets, but in context, they
> >> are not played or heard as triplets.
> >>
> >> My only comment in this discussion is that the Lilypond code to
> >> represent this short passage should be as clear as the printed score I
> >> am reading.
> >
> > try \times 8/12 { ... }
> >
> > (by default, this will probably display as 12:8 above the notes, which
> > can be tweaked to just show 12)
> >
> > IMHO, this is an argument for a mathematical notation: You must know what
> > you are doing to notate the music (i.e., multiplying durations with
> > 8/12), just saying that a 12 should be displayed above would make it
> > difficult to maintain the .ly code.
>
> Here's a different idea: instead of specifying the ratio for a tuplet or
> set of tuplets, what about specifying the duration of a tuplet, and
> letting LP determine what number appears over the beam?
>
> For example, where we now use
>     \times 2/3 { a8 b c }
> to get a triplet of three quavers in the time of two, instead have
>     \tuplet 4 { a8 b c }
> LP can calculate the ratio (and hence what should appear over the
> tuplet) from the time given before the {...} and the cumulative time of
> the notes inside the {...}.
>
> This would mean that users do not need to work out the ratio, they just
> need to know how long the tuplet should last. Further to this idea would
> be to allow an internal division inside the {...}, so that multiple
> tuplets could be entered, maybe something like \tuplet 4 { a8 b c ! c4
> a8 ! b8 c4 }. (I've used  !  only for explaining the idea - I'm NOT
> advocating it as the desired syntax.)
>
> This would mean that for the Beethoven snippet in David Fedoruk's post,
> instead of
>
> bf16[d, f ef] \times 4/5 {d16[ ef f g a]} \times 8/12 {bf32[a c bf d c
> bf a g f g ef]}
>
> you would put
>
> bf16[d, f ef] \tuplet 4 { d16 ef f g a ! bf32a c bf d c bf a g f g ef }
>
>
> Just a thought!

Unfortunately, the number above does not always follow from the duration. 
E.g., the factors 2/3 and 4/6 are mathematically equal, but give different 
numbers. It is probably difficult to define when to use 4/6 and 2/3, 
respectively (e.g., I guess {c8[ c16 c c8]} could have either a 3 or a 6 
above it, depending on context)

-- 
Erik