Re: TimeSignature with note in denominator

[Kieren MacMillan]

Hi Lukas,

> When Thomas Adès switches from 4/4 to 4/5, there is no way of knowing which 
> "graphical" note length (combination of notehead style and flag count) is 
> supposed to be used for the basic unit (of which 4 make up a bar, and of 
> which five equal the duration of a semibreve).

When someone writes a [numeric] time signature 4/4 — with four “naked” quarter 
notes in the measure completely filling up that measure — the performer can 
work out that 4 represents a quarter-note duration. Replacing the numeric 
denominator "4" with a quarter-note glyph conveys exactly that information.

When someone writes a [numeric] time signature 2/6 — with two “naked” quarter 
notes in the measure completely filling up that measure — the performer can 
work out that 6 is “halfway between 4 and 8”, and thus represents a 
triplet-eighth-note duration. Replacing the numeric denominator "6" with a 
triplet-eighth-note glyph conveys exactly that information.

Both of these situations reflect exactly the accepted definition of time 
signature: “how many beats (pulses) are contained in each measure (bar), and 
which note value is equivalent to a beat”.

Please explain the flaw in my logic, because it seems perfectly clear to me 
both in my text description(s) and in that snippet I sent earlier.

Thanks,
Kieren.