Bible Notes Online - 1-Chronicles 6 - ESV
Commentary

v1-15: The line of Levi, listing the high priests, in the line of Aaron.

Eleazar, Num 20.28; Phinehas, Josh 22.30-32; Judg 20.28 may be a reference to his son or grandson; Zadok, 2 Sam 8.17; 15; Ahimaaz, 2 Sam 20.25; Azeriah, 1 Kings 4.2; Hilkiah, 2 Kings 22; the list continues until the captivity in Babylon.

v16-30: The list of the other clans of Levi, and also the genealogy of Samuel.

v31-32: David was responsible for introducing music into the worship of God in a wider way. Musicians were Levites, i.e: joined to the Lord; a reminder that the first qualification for service is faith, not ability. Three singers are mentioned; Heman (v33), Asaph (v39), Ethan (v44), with their families.

v33-38: The genealogy of Heman, the first of the singers. This list seems to be more complete than that in v25-27. The key is that the genealogies of the three lead singers is established.

v39-43: The genealogy of Asaph, the associate of Heman.

v44-47: The genealogy of Ethan.

v48-53: The Levites performed the various responsibilities of service in the tabernacle, and then the temple. Aaron's son, the high priests, had the special role of offering sacrifices.

v54-81: The names of towns provided from the tribes for the Levites to live in.

Amongst these towns is Beth-Shemesh (v59), referred to in 1 Sam 6.12-15, where the ark returned to after being captured by the Philistines.

Note also that some from Kohath lived in Ephraim, as in 1 Sam 1.1, where Elkanah lived in the mountains of Ephraim.