Unless you happen to be listening to Carter, Cowell, Ferneyhough, Johnston, Nancarrow, or anyone who has ever happened to use a quintuplet (Chopin, Elvin Jones, maybe Al Pacino in "Heat")

-Jonathan

Or Beethoven, Schubert, Brahms, Tchaikovsky Wagner, Mahler, Strauss, Bartok, Schoenberg, Berg, Stravinsky, Prokofiev, Ravel, Debussy, etc., not to mention the more "temporally advanced" folks you mentioned. Plenty of jazz, and decent metal splits beats into fives, and you can't play in a drum corps without perfect subdivision chops... sometimes quintuplets are called "20th notes."

But if you want pieces that make heavy use of quintuplets, you would want to check out Carter (start with the string quartets, for instance). Tuplets are often used to allow several people to play music in different tempi while each attending to a "master pulse." I just played a recorder motet where the the low voice was in 3/2, the middle voice in 2/2, and the upper voice in the equivalent of 5/10 time. Or, in Carter, often the old quintuplet becomes the new 16th note and the music proceeds at a faster tempo.

There are plenty of composers who do the same simply using time signatures. I've conducted pieces which go fluidly from one meter to the next -- 3/4 5/6 2/4 3/8 31/32 5/4 19/10 etc. It's not that hard once you get the hang of it, but it is hard to get the hang of.

I believe that most competent musicians should be able to handle rhythmic notation at least up to subdivisions of 6. Not that they can usually; but I believe it should be the case -- one can practice rhythm anywhere.

In addition you can check out Stockhausen, Babbitt, Boulez, Wuorinen, or most anyone who structures rhythm parametrically. (pun) Or, for an extremely rich but different orientation, check out Carnatic (South Indian) classical music -- look up "Korvai" for instance.

Matt