Angel of God is a traditional prayer for the intercession of the guardian angel, often taught to young children as the first prayer learned. It serves as a reminder of God's love, and by enjoining the guardian angel to support the child in a loving way, the prayer echoes God's abiding love. Scholars suggest this prayer’s origin lies in 12th-century England, specifically in a poem by Reginald of Canterbury.

This composition consists of several movements, each differing in the number of voices as well as in musical style. Each movement may also be performed independently, and the composer has provided optional voice parts to allow for greater flexibility in performance.

After a unison introductory chant, a composer’s own invention, the piece continues with four-part polyphony for low equal voices over a cantus firmus. The cantus firmus then appears in the upper voice of a five-part setting, stylistically paying tribute to Thomas Tallis. Next comes a duet in thirds, creating a meditative atmosphere, which grows into a trio with chromatic movement. This is paired with a responsory in the lower voices, gradually building tension toward a tutti fortissimo section, where the chant is richly and sharply harmonized, with a soaring soprano line contrasted by an exposed responsorial duet in the lowest voices. The piece concludes with an Amen, developed polyphonically from the motif of the final two bars.