Arépétiteur (from the French verb répéter meaning 'to repeat, to go over, to learn, to rehearse')[1] is an accompanist, tutor or coach of ballet dancers or opera singers. The feminine form is répétiteuse.
Inopera, a répétiteur is the person responsible for coaching singers and playing the piano for music and production rehearsals.[1] 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.[2]
Inballet, a répétiteur teaches the steps and interpretation of the roles to some or all of the company performing a dance.[1][3] 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.
The dictionary definition of répétiteur at Wiktionary