5. chant—literally, "mark distinct sounds and tones."
viol—the lyre, or lute.
invent … instruments … like David—They fancy they equal David in musical skill (1Ch 23:5; Ne 12:36). They defend their luxurious passion for music by his example: forgetting that he pursued this study when at peace and free from danger, and that for the praise of God; but they pursue for their own self-gratification, and that when God is angry and ruin is imminent.