Albert Barnes Commentary 2 Kings 3:15

"But now bring me a minstrel. And it came to pass, when the minstrel played, that the hand of Jehovah came upon him." — 2 Kings 3:15 (ASV)

Music seems to have been a regular accompaniment of prophecy in the "schools of the prophets" (marginal reference), and an occasional accompaniment of it elsewhere (Exodus 15:20).