Piano Accompanist Job Description. Duties and Responsibilities. Provide piano music at worship services, including Sunday, mid-week services (Advent, Christmas, Lent, Holy Week etc.), and all special occasions of worship services where the piano is the primary instrument used. This includes all liturgical aspects of the worship including prelude, postlude, offertory, etc. 1 week off a month. typically plays 3 Sundays a month as well as special se...