Accelerando – Musical Tempo Acceleration

Overview

Accelerando, often abbreviated as accel., is an Italian term directing musicians to increase the tempo gradually. Unlike a sudden tempo shift marked by a new metronome indication, an accelerando implies a smooth, continuous acceleration that may span a few measures or an entire section. The exact rate of increase is left to the performer’s interpretation, guided by the musical context, phrasing, and expressive intent.

In written scores the instruction is typically placed below the staff, sometimes accompanied by a dashed line or a hairpin (↗) to visually indicate the direction of the change. Accelerandos are employed to heighten tension, propel a piece toward a climax, or transition between contrasting sections.

History / Origin

The word accelerando derives from the Italian verb accelerare, meaning “to accelerate.” Italian musical terminology became standard during the Baroque period (1600–1750) as Italy was a dominant center for compositional practice and publishing. Early examples appear in the works of composers such as Arcangelo Corelli and Johann Sebastian Bach, who used the term to shape expressive pacing in concerti and keyboard works.

By the Classical era, accelerando had become a conventional articulation mark, appearing in the scores of Haydn, Mozart, and later Beethoven. Its use expanded further in the Romantic period, where composers like Liszt and Wagner employed broad accelerandos to intensify dramatic narratives.

How It’s Used

Accelerando is found in virtually every genre that employs Western notation, from Baroque suites to contemporary film scores. In orchestral and chamber music it often guides large ensembles through tempo changes that would be difficult to coordinate with a metronome alone. In solo instrumental music—such as piano études, violin caprices, or guitar studies—the performer must internally gauge the speed increase, often using breath, bowing, or fingering cues.

Notation can vary: a simple “accelerando” may be written above the staff, a dashed line may extend across the measures, or a hairpin arrow may be drawn. In jazz charts, the term is sometimes replaced by “speed up” or indicated numerically with a series of tempo markings.

Why It Matters

Accelerando contributes to the emotional arc of a piece. By subtly increasing tempo, composers can create a sense of urgency, excitement, or forward motion without altering other musical parameters. Listeners often perceive accelerandos subconsciously as a build‑up toward a climax, as heard in the famous “Mars” movement of Gustav Holst’s *The Planets* or the opening of Beethoven’s *Symphony No. 5*.

For performers, mastering accelerando is a matter of technical control and expressive judgment. It requires coordination with ensemble members, awareness of pulse, and the ability to transition smoothly into the new tempo, often aligning with a subsequent tempo marking such as ritardando or a tempo.

Common Misconceptions