Répétiteur

A répétiteur (from the French verb répéter meaning 'to repeat, to go over, to learn, to rehearse') is an accompanist, tutor or coach of ballet dancers or opera singers. The feminine form is répétiteuse.

Opera
In opera, a répétiteur is the person responsible for coaching singers and playing the piano for music and production rehearsals. When coaching solo singers or choir members, the répétiteur will take on a number of the roles of a vocal coach: advising singers on how to improve their pitch and pronunciation, and correcting note or phrasing errors.

Répétiteurs are skilled musicians who have strong sight-reading and score reading skills. In addition to being able to sight read piano parts, a répétiteur can play on the piano an orchestral score reducing it in real-time (orchestral reduction), by reading from a large open score of all of the instruments and voice parts. Répétiteurs are also skilled in following the directions of a conductor, in terms of changing the tempo, pausing, or adding other nuances.

Ballet
In ballet, a répétiteur teaches the steps and interpretation of the roles to some or all of the company performing a dance. Several late 20th-century choreographers, such as George Balanchine, Jerome Robbins, Gerald Arpino and Twyla Tharp, have established trusts and appointed conservators—hand-picked dancers who have intimate knowledge of particular ballets—as répétiteurs of their works.