This is Feargal King’s setting of Psalm 122 in Voices As One Volume 2.. It has three different tunes for the verses the cantor has to learn. There are harmony lines in the refrain and second verse. The third verse is longer and bears no musical resemblance to the rest of the song. The refrain is very simple so the assembly should join in.
The sheet music can be purchased at WLP where the text is in their sample pages. There is a sound sample to listen to here.
I did my backing before I heard the sample but must have known it was a rock song with saxophone parts.