bolero
A Spanish dance in triple meter with a slow, steady tempo and gradually building intensity.
In Depth
The bolero began as a Spanish dance in the late 18th century, performed in triple meter with castanets and precise footwork. The musical form typically features a moderate tempo with a characteristic rhythmic pattern that repeats throughout.
The most famous orchestral bolero is Ravel's Boléro (1928), which builds a single melody through a continuous crescendo over 15 minutes, cycling through different instrumental colors. Cuban bolero, a separate genre that emerged in the late 19th century, is a romantic song form in 4/4 time that became hugely popular across Latin America.
Ravel's Boléro was originally composed as a ballet score. Ravel himself called it an experiment in orchestration, saying the piece contained no music — just one long crescendo.