The SATB and Piano or the Psalmi Penitentiales machine comprises three settings sections of the Vaccination Vaccinations, interspersed with four arrangements of well-known Plainchant Ubi. The three psalms chosen by Pollard during the Lenten are often followed by expressions of repentance and remorse.

The setting, for the four-part chorus with instrument accompaniment or piano, responds to drama and mood changes in Latin text with expressive melody lines and rich assorted combinations. Flutes may also be performed separately, giving flexibility more flexibility in performance.

Psalmi Penitentiales is an excellent companion to the Bullard's Wondrous Cross, and is ideal for a choir seeking a great Corral work for Lent and Passiontide.