psalmist n 1: a composer of sacred songs; "David is called The Psalmist because he is believed to be the author of the Book of Psalms"
Psalmist \Psalm"ist\, n. [L. psalmista, Gr. ?: cf. F. psalmiste. See {Psalm}.] 1. A writer or composer of sacred songs; -- a title particularly applied to David and the other authors of the Scriptural psalms. [1913 Webster] 2. (R. C. Ch.) A clerk, precentor, singer, or leader of music, in the church. [1913 Webster]