Kurtzman, who edited a publication of the work for Oxford University Press, notes: "...it seems as if Monteverdi were intent in displaying his skills in virtually all contemporary styles of composition, using every modern structural technique". Monteverdi achieved overall unity by using the Gregorian plainchant as a cantus firmus, for the beginning, the psalms, the litany and the Magnificat. This "rigorous adhesion to the psalm tones" is similar to the style of Giovanni Giacomo Gastoldi, who was choirmaster at the Basilica palatina di Santa Barbara at the ducal palace in Mantua. Whenham summarised about the use of chant: