I don't know if you guys know who Scott Aniol is; he's Chair of the Worship Ministry Department of Southwestern Baptist Theological Seminary and blogs at religiousaffections.org. He is influential in many circles, very smart and very talented and very non-EP! But he has this to say: If you were in Ephesus when Paul’s letter arrived, and you had a Bible in your church, it was a Septuagint. As you browsed through the Book of Psalms three terms would keep appearing in the titles and you would be quite familiar with them – psalmos, humnos and ode. In 67 Psalms the word psalmos is found eg Psalm 23; in 6 titles the word humnos appears eg Psalm 8; in another 35 Psalms ode is in the title eg Psalm 45. Furthermore, in 12 Psalms the words psalmos (psalm) and ode (song) are found together in the title e.g. Psalm 65, and in 2 titles psalmos (psalm) appears with humnos (hymn) eg Psalm 6. If you had studied the title of Psalm 76 all three terms are found in the Septuagint title, ‘For the end, among the hymns, a psalm for Asaph; a song for the Assyrian’. The Ephesian Christian would know that one Psalm could be a psalm and a song, or even a psalm and a song and a hymn together. All three terms were found in the titles of the Psalms and even in the title of one composition in the Book of Psalms. Paul exhorted them in biblical terms they were familiar with. http://religiousaffections.org/news-reviews/of-psalms-hymns-and-spiritual-songs-and-the-rpw/ The fact that someone of his stature and convictions says this publicly and teaches his students this is something to appreciate.