Adam Clarke on 1 Samuel 18:6

When David was returned - This verse connects well with the 54th verse of the preceding chapter; and carries on the narration without any break or interruption. See the notes on 1Sam 17:54.

The women came out - It was the principal business of certain women to celebrate victories, sing at funerals, etc.

With instruments of music - The original word (שלשים shalishim) signifies instruments with three strings; and is, I think, properly translated by the Vulgate, cum sistris, "with sistrums." This instrument is well known as being used among the ancient Egyptians: it was made of brass, and had three, sometimes more, brass rods across; which, being loose in their holes, made a jingling noise when the instrument was shaken.