I was thinking that a handful of Balanchine's ballets are made to music whose composer is explicitly referencing, if not outright adapting, the music of another. Can you name them? Some are easy...and I've left out Hershey Kay's nods to Sousa and Gershwin.
1) Tchaikovsky's nod to Mozart
2) Stravinsky's nod to Tchaikovsky
3) Schoenberg's nod to Brahms
4) Bizet's nod to Gounod
5) Webern's nod to Bach
6) Stravinsky's nod to Gesualdo
7) Ravel's nod to Couperin
8) In a very popular seasonal ballet, Tchaikovsky makes a nod to Schumann.
Are there others I'm forgetting?