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 on 05/31/17 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