There are an awful lot of Pentecost songs in Gather 3rd ed. and, surprisingly, a few that haven’t been blogged here yet.
This is Veni Creator Spiritus by Rabanaus Maurus (c9) in a translation by John Webster Grant. The tune is chant mode VIII and here arranged by Richard Wojcik.
More than you will ever want to now about this hymn text is here, including two of the stanzas of Grant’s translation right at the end of the article. A few more verses set to a different tune are here.
If you are wondering how to keep ancient tunes copyrighted you may wish to purchase Steven Janco’s further arrangement of Richard Wojcik’s adaptation of a chant mode at GIA.
Nonetheless, Wojcik has my thanks for a metrical setting of chant, which helps BIAB a lot. I’ll even forgive the triplets.