tempo [Ital., = time], in music, the speed of a composition. The composer's intentions as to tempo are conventionally indicated by a set of Italian terms, of which the principal ones are presto (very fast), vivace (lively), allegro (fast), moderato (moderate), andante (moderate, literally a "walking" tempo), adagio (slow), lento (slower than adagio ), and largo (very slow); accelerando (increasing the speed) and ritardando (slowing down) are directions to alter the tempo momentarily and are canceled by a tempo. Since Beethoven's time many composers have given metronomic indications, which, despite their seeming infallibility, are often misleading, and tempo remains a point of subjective interpretation. Acoustical factors influence the choice of a tempo but account less for the divergence between different performances than does the performer's interpretation of the work.
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