The text of this type of nonmetrical hymn is taken from Biblical text other than the Book Of Psalms
In 1562 John Day printed the Book of Psalms with psalm texts translated by ... 
for congregational singing it was not taken up by the "nonconformist" churches... [DOC] [TLE] Canticle dictionary definition | canticle defined - YourDictionary [PAR] A song or chant, especially a nonmetrical hymn with words taken from a biblical 
text other than from the book of Psalms.