Re: bar checks and independent time signatures

[David Wright]

Quoting Michael Collins (address@hidden):
> A couple days ago, I described a problem with a piece for two staves in
> independent time signatures.  After consulting this post, I moved the timing
> translator and bar line engraver out of the score context and into the staff
> context.  While the midi compiles properly, the music in the pdf runs off the
> page.  

As far as the midi is concerned, all LP has to do is convert the first
list of notes into durations each of one second, and the second list
into decreasing durations from 4 seconds to 1/4 second. If those
durations are rounded to a resolution that midi can manage, well,
how would your ears know?

On the other hand, you want to display your lists of notes in musical
notation. That's easy for the first list as the notes have pitches and
durations that fit into the patterns we call music. The second list
also has conventional pitches, but the relative durations of the notes
are defined by you in a non-musical manner: the list has no musical
rhythm. Because musical note-durations are notated through their
rhythmical relationship, there is no defined method of notating your
list as defined.

The same would be true of speech. Yes, you can notate the stresses of
poetry, but you can't notate the durations of the actual syllables.
(Well, you *could* notate the syllables using the conventions of
music, but a literal interpretation of the score would not sound
anything like natural speech.)

> Lilypond says that the bar checks in the top voice are failing.  I suspect 
> that
> this is the root of the problem.  I've run versions of the code with each of
> the two voices commented out.  When the voices play separately, the pdf output
> stays on the page.  Something about combining the two voices is problematic.
> 
> I'm genuinely at a loss, since moving the timing translator to the staff
> context should make the voices completely independent.  Any advice?

Accepting the peculiarities of your second list, and the manner in
which you have coerced LP into notating it (why the mixture of
glyphs?), you can of course print the two parts on separate staves.
However, as soon as you bracket them together, you are indicating that
the staves all commence simultaneously. You can get away with not
spanning the non-initial barlines, but each brace carries a meaning.
As soon as six beats have passed, there is no further place at which
you can write a brace. So, no new lines.

To demonstrate this, take a pair of scissors and cut your score at
some convenient place so it doesn't run off the page. Now draw a brace
at the left end of the last part. You've now indicated that the first
note on each staff starts at the same time. Any offset will look like
a typesetting mistake, and will carry no timing information.

Cheers,
David.