English 'allegro' is borrowed from Italian, where it means 'cheerful' and 'lively,' descending from Latin 'alacer' (eager, brisk) — originally a description of mood rather than speed, only gradually narrowing to a strict tempo indication as musical notation became more precise.
A musical tempo direction indicating a fast, lively pace, typically between 120 and 156 beats per minute.
From Italian 'allegro' (lively, cheerful, brisk), from Latin 'alacer' (lively, eager, brisk). The Latin adjective's earlier form may have been 'alicer,' and its ultimate origin is uncertain, though some scholars connect it to PIE *h₂el- (to grow, to nourish). In Italian, 'allegro' retained its sense of cheerfulness and liveliness, and when adopted into musical notation in the seventeenth century, it indicated not just speed but a character of spirited
The original meaning of 'allegro' in Italian musical scores was not purely about speed — it indicated cheerful, bright character. A seventeenth-century 'allegro' could be slower than a modern one. It was only through the eighteenth and nineteenth centuries that tempo markings hardened from descriptions of mood into precise speed indications, and the metronome (invented