Divrey Hayamim Alef 25:1

1 5 Moreover Dovid and the sarim of the tzava separated for avodah of the Bnei Asaph, and of Heman, and of Yedutun, who should prophesy with kinnorot, with nevalim, and with cymbals; and the number of the workmen according to their avodah (service) was;

Divrey Hayamim Alef 25:1 Meaning and Commentary

1 Chronicles 25:1

Moreover, David and the captains of the host separated to
the service
Of singing the praises of God; this was done by the princes of the people, and the chief of the priests, who were gathered together, and before whom the lots were cast, both for priests and Levites, and now here for the singers, see ( 1 Chronicles 22:2 ) ( 24:6 ) and those that were separated were

of the sons of Asaph, and of Heman, and of Jeduthun;
or Ethan, the three precentors, or chief of the singers:

who should prophesy with harps, with psalteries, and with cymbals;
sing psalms, hymns, and spiritual songs, endited by the Holy Spirit of God; which contained in them prophecies concerning things to come, particularly relating to the Messiah, of which there are many in the book of Psalms; and to the tunes of these they played on the above instruments of music:

and the number of the workmen, according to their service, was;
as follows.

Divrey Hayamim Alef 25:1 In-Context

1 5 Moreover Dovid and the sarim of the tzava separated for avodah of the Bnei Asaph, and of Heman, and of Yedutun, who should prophesy with kinnorot, with nevalim, and with cymbals; and the number of the workmen according to their avodah (service) was;

2 Of the Bnei Asaph; Zakkur, and Yosef, and Netanyah, and Asarelah, the Bnei Asaph under the hand of Asaph, which prophesied according to the order of HaMelech.

3 Of Yedutun, the Bnei Yedutun: Gedalyah, and Tzeri, and Yeshayahu, Chashavyahu, and Mattityahu, six, under the hands of their av Yedutun, who prophesied with a kinnor, to give thanks and to praise Hashem.

4 Of Heman, the Bnei Heman: Bukiyahu, Matanyahu, Uzziel, Shevuel, and Yerimot, Chananyah, Chanani, Eliatah, Giddalti, and Romamti, Ezer, Yoshbekashah, Maloti, Hotir, and Machazi’ot;

5 All these were the banim Heman the chozer (seer) of HaMelech in the devarim of Elohim, to lift up the keren. And HaElohim gave to Heman fourteen banim and three banot.