OT: notation of duplets/quadruplets in compound time

[Michel R E]

I have a passage in 12/8.
In this passage there are beats here and there with 2 notes filling a single beat (dotted quarter value beat).
I ALSO have beats where there are four notes filling a single beat.

Finale lets me write a duplet of eighth notes to fill a beat, and it also lets me insert a quadruplet of eighth notes to fill a beat.
They BOTH look right to me. And yet, at the same time it is confusing to see two eighth notes take up a single beat, and four eighth notes take up another single beat.

16th notes look wrong for the quadruplet, and I'm assuming that they really are too small a value to fill the beat. so eighths would be correct for a 4plet.

does this mean that I have to change my duplets of eighths to duplets of quarters to fill a single beat?

[David Ward]

does this mean that I have to change my duplets of eighths to duplets of quarters to fill a single beat?

Strictly, yes. In theory (but not always practice) a tuplet is supposed to add up to too much if it were not a tuplet. However, the most important thing is to be consistent - so either 2 eighths and 4 sixteenths, or 2 quarters and 4 eighths. Alternatively, you could use dotted non-tuplets, which is what I do (without question or complaint from performers).

[motet]

Elaine Gould talks about the compound-time considerations. "Traditional" notation would use eighths for the duplet and sixteenths for the quadruplet. "Contemporary" would use quarters for the duplet and eighths for the quadruplet. Personally, I use the former.

[Michel R E]

I've gone with duplets of 8ths and quadruplets of 16ths.
I tried the other way and it was just too messy.
I also tried making the duplets into simply dotted 8ths and it was more confusing than anything.

[Peter Thomsen]

Elaine Gould talks about the compound-time considerations. "Traditional" notation would use eighths for the duplet and sixteenths for the quadruplet. "Contemporary" would use quarters for the duplet and eighths for the quadruplet. Personally, I use the former.

The context makes the difference.

In the « Orgel-Büchlein » by J. S. Bach, in the double canon over « In dulci jubilo », Bach used a “contemporary” notation - and the notation makes perfect sense in the context.

One canon is notated in 9/8 - three beats, each beat sub-divided into three 8ths.

The other canon - with the cantus firmus - uses a beat sub-division of two 4trs (as in 3/2).

In this context it is clear that the triplet 8ths - with one beam - are faster, while the duplet 4trs - with no beams - are slower.

[motet]

Interesting, Peter, thanks! I think I have a tiny Lea Pocket Score of the Orgel-Büchlein somewhere--I'll have to find it.