Re: Mixed Time Signatures: Non regular alternantion between 5/8 and 8/8

[Reinhold Kainhofer]

Am Sonntag, 22. August 2010, um 11:40:14 schrieb David Bobroff:
>   On 8/22/2010 9:32 AM, fauban wrote:
> > Dear Lilypond community:
> > I am typesetting a piece in two sections:
> > The first one consists of 5/8 and 8/8 bars. Their alternaton does not
> > follow any pattern.
> > Then, the next section is always in 9/8.
> > 
> > How can I engrave one of those mixed time signatures (that is, 5/8 8/8)?
> > (Here is an example from Wikipedia:
> > http://en.wikipedia.org/wiki/Time_signature#Mixed_meters , you must
> > scroll down a bit, until you see the 3/4 6/8 signature).
> > 
> > Thank you very much!
> 
> Are you sure that you want to display a 5/8 8/8 time signature?  In the
> example you linked to the mix is 6/8 3/4 which are simply two different
> ways of organizing the same time value in each measure.  You're talking
> about 5/8 and 8/8 which are not interchangeable time values.  Assuming
> that in your mixed 5/8 8/8 section the 8th note pulse remains constant
> it would be misleading, confusing and annoying to read.  I would
> recommend changing the time signature when it is appropriate to do so.

Actually, for 20th-century music it's no uncommon to have alternating time 
signatures. I have a score of the "Psalmenproprium" by Haselböck (Verlag 
Doblinger), which very frequently has time signatures like 3/4 4/4 or even 
2/4 3/4 3/8 5/8 (yes, four different values!). There is no regularity in the 
order and length that the different meters appear in the score. 

The main problem for lilypond is not the display, since the stencil can be 
easily overridden, but rather the automatic barline feature, which needs to 
know how long a particular measure needs to be. With those alternating time 
signatures, all you know is that the measure should have a length that is in 
the list of given fractions, but you don't know which.

Cheers,
Reinhold


-- 
------------------------------------------------------------------
Reinhold Kainhofer, address@hidden, http://reinhold.kainhofer.com/
 * Financial & Actuarial Math., Vienna Univ. of Technology, Austria
 * http://www.fam.tuwien.ac.at/, DVR: 0005886
 * LilyPond, Music typesetting, http://www.lilypond.org