Hobbies Playing Music The Definition of the Italian Music Command Accelerando Share PINTEREST Email Print Image © Brandy Kraemer, 2015 Playing Music Playing Piano Tutorials Piano Chords Buying Advice Music Education Playing Guitar Home Recording By Brandy Kraemer Updated June 01, 2017 The Italian musical command accelerando (often abbreviated accel.) is an indication to gradually increase the tempo of a song until otherwise noted: The duration of an accelerando is marked by a dashed, horizontal line. An accelerando with no dashed line may be terminated with commands such as tempo primo or tempo comodo. Opposite of ritardando. Also Known As: accélérez; en accélérant (Fr) beschleunigend; schneller (Ger) Pronunciation: ack-sel'-er-AHN-doh