Au Mouvement in French Musical Terminology

In written music, there are a few languages used universally to indicate music expressions. The most common is Italian and French is a close second. German and English are also used, depending on the composer. Au mouvement falls within the French category of music terminology. 

The full French musical phrase is retour au mouvement and indicates that the music's tempo should return to its original tempo.

Sometimes the term is abbreviated as au mouvt.  Other terms that are similar to au mouvement include the Italian a tempo and the German im Zeitmass. But be careful not to confuse the term with the English term movement, which means something different altogether. 

When Au Mouvement Is Used

Sometimes in music pieces, a composer may want to change the tempo, or the speed, of a piece. For example, if a song starts out very fast but then has a slower section, the tempo must change in order to indicate to the musician the tempo is slower than it was in the beginning of the piece. Usually, this new tempo marking is temporary; when the music is returning to its previous tempo, that would be indicated with au mouvement.

This is an especially common marking in French Impressionistic music.  French composer Achille-Claude Debussy frequently wrote compositions in which the music ebbed and flowed with multiple tempo changes.

Slowing down or speeding up the music was a way of expressing the musical phrase. In order to go back to the original tempo, au mouvement is used regularly throughout his music, always bringing the musician back to the original timing of the piece.