Jamieson, Fausset and Brown on 1 Chronicles 25:5

5. Heman the king's seer--The title of "seer" or "prophet of David" is also given to Gad (1Ch 21:9), and to Jeduthun (2Ch 29:14, 15), in the words (Margin, "matters") of God.

to lift up the horn--that is, to blow loudly in the worship of God; or perhaps it means nothing more than that he presided over the wind instruments, as Jeduthun over the harp. Heman had been appointed at first to serve at Gibeon (1Ch 16:41). But his destination seems to have been changed at a subsequent period.

God gave to Heman fourteen sons and three daughters--The daughters are mentioned, solely because from their musical taste and talents they formed part of the choir (Psa 68:25).