sports actors: Who co-starred as Gale Sayers in Brian's Song?

Questions

What popular song was based on Chopin's Polonaise, Opus 53?

The Opera Don Giovanni was based on what character?

In 1723, J .S. Bach left Cothen to take up a new job in which city?

When Gershwin's Rhapsody in Blue was premiered in 1924, whose orchestra accompanied?

By what first name was the French composer Berlioz known?