Recently I was privileged to be in the same room with six terrific musicians singing Dufay's Ave regina caelorum mass. What incredible rhythmic exuberance!
One of my favorite proofs of our era's narrowing rhythmic spectrum dates from back in the 70's when, in a coffee shop, I heard something vaguely familiar coming over the Muzak and had to stop to figure out that it was the well-known Bach Minuet in G with a extra beat added to each bar. Yow.
Someone commented recently on an evening at Barbes listening to Rachelle Garniez that it was so refreshing to hear songs in 3/4 time.