The king's seer — He is called the king's seer, either because the king took special delight in him; or because he frequently attended the king in his palace, executing his sacred office there, while the rest were employed in the tabernacle. In the words — To sing Divine songs as were inspired by God to the prophets or holy men of God. The horn — To praise God with the sound of a trumpet or some other musical instrument made of horn, which being a martial kind of music, might be most grateful to David's martial spirit: tho' he was also skilled in other instruments of music which he used in the house of God.
Related Commentaries of 1 Chronicles 25:5
1 Chronicles 25:5
5 All these were the sons of Heman the king's seer in the wordsd of God, to lift up the horn. And God gave to Heman fourteen sons and three daughters.