Boléro is a musical composition by Maurice Ravel that is known for its continuous crescendo and unchanging ostinato rhythm played on one or more snare drums. The piece features two melodies, each played twice alternately, with the first melody being diatonic and the second melody introducing more jazz-influenced elements. The melody is passed among different instruments, leading to a variety of timbres. This article provides a detailed analysis of the piece, including its structure, instrumentation, and musical themes.