John Calvin Commentary Psalms 33:3

"Sing unto him a new song; Play skilfully with a loud noise." — Psalms 33:3 (ASV)

Sing unto him a new song. Since the Psalmist later discusses the mighty works of God, and particularly the preservation of the Church, it is not surprising that he exhorts the righteous to sing a new song, that is, a rare and choice song. The more closely and diligently believers consider the works of God, the more they will exert themselves in praising him. It is no common song, therefore, that he exhorts them to sing, but a song corresponding to the magnificence of the subject. This is also the meaning of the second clause, in which he urges them to sing loudly. In this sense, I understand the Hebrew word היתיב, heytib, although others refer it instead to the proper setting of the notes.