John Gill 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)

So the Levites appointed Heman the son of Joel
The grandson of Samuel the prophet, (1 Chronicles 6:33)

and of his brethren, Asaph the son of Berechiah ;
a famous singer, often mentioned in the Psalms, (1 Chronicles 6:39)

and of the sons of Merari their brethren, Ethan the son of Kushaiah ;
the same with the son of Kishi, (1 Chronicles 6:44) , these were the chief of the singers.