Isaac displays his genius for cantus firmus writing in using two chants as the basis for this motet. The plainsong alleluia for the corresponding mass (Liber Usualis, 1952, p.880) as well as the following more familiar sequence Veni sancte Spiritus are both evident in this polyphony – the alleluia chant in the alleluia verse and the sequence chant quoted by the soprano in the alleluia refrain – albeit with an altered semifinal tone. The Formschneider print has a printing error in that the soprano part shows C3 at the beginning of the verse. Pätzig (1956) shows two manuscript sources with the soprano in ¢3 as the bass voice is. This motet clearly shows the transition happening throughout the Renaissance as modality began its transition to tonality. The harmony has several different interpretations, again thanks to the variants between the print and the manuscripts.
Alleluia. Veni sancte Spiritus reple tuorum corda fidelium et tui amoris in eis ignem accende. Alleluia.
Alleluia. Come Holy Spirit into the hearts of Your faithful, and kindle in them the fire of Your love. Alleluia.