accelerandos

Accelerando is a musical term instructing a gradual increase in tempo. The plural accelerandos is used to refer to two or more such speed-ups within a piece; in Italian sources the corresponding plural is accelerandi, but accelerandos is common in English-language scores and discussions. The term derives from accelerare, to hasten.

Notation and interpretation vary. Accelerando is usually written as the word accelerando (or accel. in abbreviated form) in the score. Musicians may also see a hairpin opening up between notes or bars to indicate a gradual quickening, sometimes continuing until a new tempo is reached or until an a tempo marking resumes the previous speed. The exact rate of acceleration is left to performer judgment or is specified by the editor in some editions.

Usage and effects. An accelerando is employed to create momentum, rising intensity, or narrative drive, and it can occur over a short passage or span a longer section. In ensemble performance, coordination is important to ensure a smooth transition to the next tempo or section. While traditionally a steady, gradual speed-up, contemporary practice may vary in abruptness depending on style, tempo relationships, and expressive goals.

Related terms. Rallentando or ritardando denotes a gradual slowing, while stringendo refers to a quickening or pressing forward, often overlapping with accelerando in expressive passages. A tempo may follow an accelerando to reaffirm the established speed.