Mass in A dur, Op. 12

One of his most magnificent sacred compositions is the Solemn Mass in A dur, Op. 12, which he composed in 1860 in the traditional movements of Kyrie eleison ("Lord have mercy"), Gloria ("Glory"), Credo ("Creed") , Sanctus ("Holy") and Agnus Dei ("Lamb of God"). The premiere was held to great acclaim by the parishioners on 2 April 1861 at St. Clotilde. Subsequently Franck revised the work. The Credo and Agnus Dei underwent significant changes, and the original O Salutaris was later replaced by the participial Panis Angelicus. This final version was performed again in the same basilica on 24 April 1878.

As it should be, the organ is the foundation instrument responsible for both sustaining the voices and adding contrapuntal polyphony. To it the composer also includes instruments: cello, harp and double bass. The mass was written for a three-voice choir - sopranos, tenors and basses. The soloists are also three - soprano, tenor and bass. This trinity is symbolic of the Holy Trinity (God the Father, God the Son and God the Holy Spirit). Cesar Franck was amazingly masterful in his rendering of the sacred word in the construction of the musical and semantic sacred dramaturgy of the mass with the skillful interweaving of solo and choral voices. The most popular section of the work in its second edition is the Panis angellicus (" Angelic Bread"). According to one of Franck's biographers, its lovely melody originated as an improvisation during the 1861 Christmas service. In 1872 the composer turned it into a motet for soprano (or tenor), organ, harp and cello, which he published that same year and then included it as part of the Solemn Mass, Op. 12.