Ballet music was an accompaniment for the solo and ensemble dances. Tchaikovsky's Swan Lake was the first musical ballet piece to be created by a symphonic composer. Following the initiative of Tchaikovsky, ballet composers were no longer writing simple, easily danceable pieces. The focus of a ballet was no longer solely the dance; the compositions behind the dances began to take an equal prevalence. In the late 19th century, Marius Petipa, French ballet choreographer and dancer, worked with composers such as Cesare Pugni to create ballet masterpieces that boasted both complex dance and complex music.