Pierre de la Rue's 'Missa pro defunctis' is one of the earliest polyphonic settings of the requiem and became the best-known work of this genre during the Renaissance. The impressively low range of parts of the Mass vividly represents the position of the sinner knocking at heaven's gate.
Alongside this is la Rue's 'Missa de Beata Virgine', in which the missing Proprium parts of the Mass have been completed by Gregorian chant from a manuscript of St. Thomas's Church in Leipzig. The result is a Mass of St. Mary as it might have sounded in (then still Catholic) Wittenberg around 1500.