Psalms - the book of Psalms was the songbook of the early church, continuing
a tradition from synagogue worship.
Hymns - the hymns of the early church were new, enabling the church to sing about Christ and important doctrines connected to him.
Spiritual songs - these songs were based on the word ‘alleluia’, in particular the last syllable, ‘ia’, and were freer and more spontaneous, in response to the Spirit.
This kind of singing came to be called ‘jubilus’.
From Robert Webber’s Enter His Courts with Praise, pp. 3-4.