Accelerando vs. Ritardando — What's the Difference?

Accelerando is a 2005 science fiction novel consisting of a series of interconnected short stories written by British author Charles Stross. As well as normal hardback and paperback editions, it was released as a free e-book under the CC BY-NC-ND license.

Gradually slowing in tempo; retarding. Used chiefly as a direction.

Gradually accelerating or quickening in time. Used chiefly as a direction.

(music) Gradually decelerating the tempo of a piece of music, especially at the end of the piece.

An accelerando passage or movement.

(music) Having a gradually decelerating tempo.

(music) A tempo mark directing that a passage is to be played at an increasing speed.

(music) An instance of gradually decelerating the tempo of a piece of music.

(music) A passage having this mark.

Retarding; - a direction for slower time; rallentado.

(by extension) Accelerating or exponential advancement or development (of a thing).

Gradually decreasing in tempo

(music) With a gradual increase in speed.

Gradually accelerating the movement.

A gradually increasing tempo of music;

Gradually increasing in tempo

With increasing speed;