A gradual increase in tempo across a passage, written accel. or accelerando, which speeds the pulse up step by step.
Also called: accel., accel, speeding up
Accelerando is Italian for speeding up. It marks a gradual increase in tempo across a passage, written accel. or with a dashed line running over the bars. The change is continuous. The pulse does not jump to a new speed but accelerates until a new marking takes over or the passage ends. A passage in 4/4 that starts at 80 beats per minute and ends at 100 has beats that shorten steadily, so the first and last beats differ noticeably in length. Composers use accelerando in fast passages, in codas and in climaxes, where a rising pace adds tension. Its opposite is ritardando.
Fundamentals
Italian tempo words run from slow to fast. Approximate beats-per-minute bands for each, the modifiers and transitions that change them, and why a metronome number needs a time signature.