וּזְכַרְיָ֨ה וַעֲזִיאֵ֜ל וּשְׁמִֽירָמ֤וֹת וִֽיחִיאֵל֙ וְעֻנִּ֣י וֶֽאֱלִיאָ֔ב וּמַעֲשֵׂיָ֖הוּ וּבְנָיָ֑הוּ בִּנְבָלִ֖ים עַל־עֲלָמֽוֹת׃
Rashi on I Chronicles
And Zechariah and Aziel, etc. Those, mentioned in the preceding verse as being gate sentries, were here transferred to become singers.
Rashi on I Chronicles
over alamoth over those instruments with which they played those psalms, entitled: “To the conductor, on alamoth, etc.”