In his "Messe brève" Delibes did not set the "Credo" and "Benedictus" to music, but after the "Sanctus" he included a setting of "O salutaris hostia", a customary section of the "mass in France. However, the appearance of the directions "tutti" and "soli" in the Mass points to the use of a choir; the solo passages are to be sung by members of the choir, as they correspond musically to the tutti sections which follow, and are therefore to be understood as merely providing contrasting levels of sound within the movement.
