Charles Ellicott Commentary 1 Chronicles 15:17

"So the Levites appointed Heman the son of Joel; and of his brethren, Asaph the son of Berechiah; and of the sons of Merari their brethren, Ethan the son of Kushaiah;" — 1 Chronicles 15:17 (ASV)

Heman ... Asaph ... Ethan (or Jeduthun) were the precentors of David’s three choirs of Levitical minstrels (1 Chronicles 6:31–44). Heman was of Kohath, and Asaph of Gershon, and Ethan of Merari.