Tempo is the speed at which a piece of music is played, usually measured in beats per minute. A metronome marking such as quarter note equals 120 gives a precise indication; Italian terms such as allegro or adagio give a more general sense of character as well as speed.

Tempo strongly affects the expressive character of music. The same notes can feel energetic or languid depending on how fast they move. Performers and conductors choose tempos based on the composer’s markings, the acoustic of the hall, the technical demands of the music, and their own interpretive judgment.

Slight flexibility of tempo, known as rubato, is common in many styles. Sudden or gradual changes of tempo are also important structural devices. Maintaining a steady tempo when required, and shaping tempo expressively when appropriate, are fundamental performance skills.

Listeners often respond to tempo even before they notice melody or harmony.