Charles Ellicott Commentary 1 Samuel 27:4

"And it was told Saul that David was fled to Gath: and he sought no more again for him." — 1 Samuel 27:4 (ASV)

And it was told Saul. —This short statement tells us plainly that up to the moment when Saul heard that David had crossed the frontier, he had not ceased to pursue him and to seek his life. Ewald considers that it was during the residence at Gath that David exercised himself as a musician in the Gittite—that is, the Philistine—style, which he afterwards transferred from there to Judah and Jerusalem. (See titles of Psalms 8, 81, 84, “upon the Gittith.”) Gittith is a feminine adjective derived from Gath; the words possibly signify, “after the Gittith manner: some particular measure or style of Philistine music, or else the reference may be to a Philistine musical instrument.”