The Rite of Spring
The painter Nicholas Roerich talked with Stravinsky about the idea for this ballet in 1910. Stravinsky started writing down musical ideas while he was still working on his ballet The Firebird.  Then he worked on Petrushka. In 1912 he was able to concentrate on The Rite of Spring.  All these ballets were composed for Sergei Diaghilev's Ballets Russes.