Scored for string orchestra and bell (only a single chime is used, on the pitch A, the tonal centre of the piece), "Cantus" exemplifies Pärt's tintinnabuli style, using only the pitches of a single A minor scale. The work is based on a simple idea, a descending A-minor scale, and is in the form of a prolation canon, an old technique which Pärt also uses in the work "Festina Lente" ("Hurry slowly"). It is in 6/4 meter and alternates long and short notes.