Tempo

In musical terminology, tempo (from Italian for 'time'; plural 'tempos', or tempi from the Italian plural), measured in beats per minute, is the speed or pace of a given composition, and is often also an indication of the composition's character or atmosphere. In classical music, tempo is typically indicated with an instruction at the start of a piece (often using conventional Italian terms) and, if a specific metrical pace is desired, is usually measured in beats per minute (bpm or BPM). In modern classical compositions, a "metronome mark" in beats per minute, indicating only measured speed and not any form of expression, may supplement or replace the normal tempo marking, while in modern genres like electronic dance music, tempo will typically simply be stated in bpm.

Tempo (the underlying pulse of the music) is one of the three factors that give a piece of music its texture. The others are meter, which is indicated by a time signature, and articulation, which determines how each note is sounded and how notes are grouped into larger units. While the ability to hold a steady tempo is a vital skill for a musical performer, tempo is malleable. Depending on the genre of a piece of music and the performers' interpretation, a piece may be played with slight variations in tempo, known as tempo rubato, or significant variations. In ensembles, the tempo is often maintained by having players synchronise with a conductor or with a specific instrumentalist, for instance the first violin or the drummer.

Measurement

Although tempo is described or indicated in many different ways, including with a range of words (e.g., Slowly, Adagio, Quickly, Allegro), it is typically measured in beats per minute (bpm or BPM). For example, a tempo of 60 beats per minute signifies one beat per second, while a tempo of 120 beats per minute is twice as rapid, signifying two beats every second.