John Gill Commentary 1 Chronicles 6:33

"And these are they that waited, and their sons. Of the sons of the Kohathites: Heman the singer, the son of Joel, the son of Samuel," — 1 Chronicles 6:33 (ASV)

Ver. 33-38. And these are they that waited with their children ,
&c.] They and their posterity, who officiated in the service of singing psalms in the sanctuary: the three heads of them were of the three families of the Levites, as follow:

of the sons of the Kohathites, Heman a singer ;
the chief of the singers, and who composed psalms and hymns, which are in the book of Psalms:

the son of Joel, the son of Shemuel ;
or Samuel. This Heman was grandson of Samuel the prophet; for whose sake his genealogy is traced up to Jacob or Israel in the following verses, and stands thus:

after Samuel, Elkanah, Jeroham, Eliel, Toah, Zuph, Elkanah, Mahath, Amasai, Elkanah, Joel, Azariah, Zephaniah, Tahath, Assir, Ebiasaph, Korah, Izhar, Kohath, Levi, Israel.