In a sense, music’s function as a signal extends, in later history, to summoning and dismissing spirits. There seems to be a common belief, at least during king Saul’s time, that good music serves as a signal for bad spirits to leave (1 Samuel 16:14-16). And, indeed, this theory becomes reality when David plays.
And whenever the harmful spirit from God was upon Saul, David took the lyre and played it with his hand. So Saul was refreshed and was well, and the harmful spirit departed from him. (1 Samuel 16:23 yet cf. 1 Samuel 19:9-10)
Also in this general period, music seems to summon God’s Spirit to inspire prophets.
David and the chiefs of the service also set apart for the service the sons of Asaph, and of Heman, and of Jeduthun, who prophesied with lyres, with harps, and with cymbals. (1 Chronicles 25:1)
[Elisha said,] “But now bring me a musician.” And when the musician played, the hand of the LORD came upon him. And he said, “Thus says the LORD….” (2 Kings 3:15-16)
The Bible says little to elaborate the link between music and prophecy (1 Samuel 10:5-6; 1 Chronicles 25:1-6). But that purpose plays its curious notes in Scripture’s grand symphony.