Heidegger's Bible Handbook: Psalms: Levitical Recipients
9. The persons to whom the Psalms were committed.
The Persons, to whom the Psalms were committed, are designated, either generally, by the term לַמְנַצֵּחַ, to the chief musician, to the Prefect, the Master of the Musicians, with the word taken from 2 Chronicles 2:2; 34:13, in which מְנַצְּחִים are ἐργοδιώκται/taskmasters or prefects of the work, from נָצַח, to press to work, to see to it that the work is diligently done: or specifically, to the choir of Jeduthun, Psalm 39; 62; 77, to the posterity of Korah, and also to Asaph and his posterity.
 2 Chronicles 2:2: “And Solomon told out threescore and ten thousand men to bear burdens, and fourscore thousand to hew in the mountain, and overseers over them (וּמְנַצְּחִ֣ים עֲלֵיהֶ֔ם) three thousand and six hundred.”  2 Chronicles 34:13: “Also they were over the bearers of burdens, and were overseers (וּמְנַצְּחִים) of all that wrought the work in any manner of service: and of the Levites there were scribes, and officers, and porters.”  See the titles of Psalm 42; 44-49; 84; 85; 87; 88.  See the titles of Psalm 50; 73-83.  See 1 Chronicles 25:1, 2; 2 Chronicles 35:15; Ezra 3:10; Nehemiah 11:22.