The music director is responsible for working with the stage director in preparing a theatre production for public performance, including casting, rehearsing the vocalists and orchestra, and conducting (and sometimes selecting) the orchestra.
In community theatre, the music director often serves in several capacities–working with singers in partnership with the director, rehearsing the cast and orchestra, and serving as conductor for all performances. However, in some cases (especially with a particularly demanding score), a separate vocal director may be used, as well as an assistant conductor.
It is essential that the production’s director and musical director have an ongoing and mutually supportive collaboration. The director communicates his or her vision of the show, and the music director uses his or her understanding of the show’s musical demands to help the director (and cast) be successful. The musical director works with the director in scheduling rehearsals, which cast members need to be there, and what the directors expect to accomplish at each rehearsal.