I have not been a strong contributor to this thread. And I have not been a strong advocate for the time signatures with a notehead in the denominator. I think all of those time signatures can be expressed just as well as a compound meter.
HOWEVER, In looking at this, is seems the lexer (and the propery timeSignatureFraction) are not semantically correct. Although the time signature looks like a fraction, it is not. A fraction has numbers in the denominator and the numerator (and strictly speaking, a fraction properly has integers in the numerator and denominator -- if they are not integers, it's a quotient, not a fraction, IIUC). And the time signature has an integer in the "numerator" and a duration in the "denominator". I'm not sure it is worth the work to get semantically correct, but semantically, \time 4/4 should not be a fraction of two integers; it should be a pair of a count and a duration. And if we had semantically correct time signature entry, Kieren's wish for a different display for the duration would be relatively straightforward, although we would potentially have an "isoduration" problem that is analogous to the "chord name semantics" problem -- there is no difference in duration between 4~4 and 2, so we couldn't preserve 4~4. Similarly, we could not tell the difference between 8.~8 and 8~8., although I can't imagine how the difference between these two representations would be important; both represent a duration of 5 eighth-notes. Anyway, like I said earlier, I'm not sure that it's worth changing the internals since they work so well for the lilypond core functionality (traditional western music), but I noticed the semantic error as I read this thread. Carl
