Jeduthun
   lauder; praising, a Levite of the family of Merari, and one of
   the three masters of music appointed by David (1 Chr. 16:41, 42;
   25:1-6). He is called in 2 Chr. 35:15 "the king's seer." His
   descendants are mentioned as singers and players on instruments
   (Neh. 11:17). He was probably the same as Ethan (1 Chr. 15:17,
   19). In the superscriptions to Ps. 39, 62, and 77, the words
   "upon Jeduthun" probably denote a musical instrument; or they
   may denote the style or tune invented or introduced by Jeduthun,
   or that the psalm was to be sung by his choir.
   

Jeduthun, his law; giving praise