Speaking to yourselves in psalms and hymns and spiritual songs. — The same words are found in Colossians 3:16, with a notable difference of application. There the idea is of teaching: “teaching and admonishing one another;” here, simply of a natural vent for emotion, especially of thanksgiving, although probably here also “to yourselves” means “to one another,” and refers, perhaps, chiefly to public worship. The well-known passage in Pliny, “Carmen dicere inter se invicem,” describes alternate, possibly antiphonal, singing of such sacred music. Of the various kinds of this music, the “psalms” and “hymns” are easily distinguished. The “psalm,” as the word itself implies, is music with instrumental accompaniment, and can hardly fail to refer to the Old Testament psalms, familiar in Jewish worship, and as we know, used in the first instance we have of apostolic worship (Acts 4:24). On their frequent use see 1 Corinthians 14:26; James 5:12. The “hymn” is purely vocal music, apparently of the whole company (see Matthew 26:30; Acts 16:25), more especially directed to praise of God, and probably designating the new utterances of the Christian Church itself. But the interpretation of the “spiritual song,” or “ode,” is more difficult. It is often considered as inclusive of the other two (as etymologically it might well be), but the genius of the passage appears to make it co-ordinate, and so distinct from them. From the use of the word “song,” or “ode,” as applied to lyric poetry, it may perhaps be conjectured that it describes more varied and elaborate music, sung by one person only — a spiritual utterance of one for the whole congregation. In a passage of Philo (2 p. 476) — quoted by Dr. Lightfoot on Colossians 3:16 — on Jewish sacred music, we read, “He who stands up sings a hymn composed in praise of God, either having made a new one for himself, or using an ancient one of the poets of days gone by.” The Christian counterpart of this might well be the “spiritual song.” To some such utterance, under the name of “psalm,” St. Paul seems to allude in 1 Corinthians 14:26, a passage dealing expressly with special spiritual gifts. “Each one of you has a psalm.” Evidently it might be strictly a “hymn” or “psalm,” though in common usage (as here) it would be distinguished from both.
Singing and making melody in your heart. — The word rendered “making melody” is the verb corresponding to the “psalm” above, as singing to the “song.” This clause is not identical but co-ordinate with the last. That described audible and public melody; this, the secret utterance of music in the soul, whether accompanying the other or distinct from it.