The term (Latin for "rejoice") comes from the opening word of the Introit for the Fourth Sunday of Lent: "Laetare, Ierusalem" . While Lent is a time of fasting and abstinence, Laetare Sunday serves as a "shot in the arm" to encourage the faithful as they approach Easter.

: Unlike other Lenten Sundays, instrumental music and altar flowers are permitted.

Finding a high-quality PDF of the Sanctus partition requires identifying the specific composer, as several masses share this name. 1. Antonio Caldara: Missa Laetare