I was reading Sigmund Mowinckel's "The Psalms in Israel's Worship". In it, Mowinckel puts foward the idea that the Psalms were created and used mostly for worship in the Temple. As to what a Psalm may have sounded like being sung in the Temple, Mowinckel suggests:
"We know nothing about the tunes in Israel's temple cult. But if we are to judge from analogies in more recent oriental music, we may assume they were quite simple. It is a safe supposition that as the 'period' (the verse) was the proper rhythmic unit, it was also the melodic one. The 'tune' was limited to the single verse, perhaps marked with a rise or fall at the end of the last line in the stanza or strophe.
According to what we know and can conjecture from later times in the East, music was not based on the octave scale. As far as we can judge, the tune was extremely simple, hardly to be called a tune, but more like a sort of recitative.
The first task of the musical accompaniment was undoubtedly to stress rythm, to 'keep time'. we may draw that conclusion both from analogies in the present, and from the old oriental and Israelite instruments of music. The psalms mention the tambourine, the cymbals, the horn, the trumpet, different kinds of lyre (R.V. harp and cithern), flute and castanets." (Mowinckel, p. 9)
