Reports of music in Rome in 1770 provide valuable evidence about performance practice at that time. He noted that even on common days the choir of the Sistine Chapel comprised a (comparatively large) average of 32 singers (SATB-8,8,8,8), roughly the same size and balance as we have chosen for this recording. Although it was sometimes the case with accompanied polychoral works (performed in the main basilica at St. Peter's, and elsewhere in Rome), for each choir to have its own continuo organ, it was also common in Roman churches for accompanied double-choir works to be underpinned by just one organ. For purely pragmatic reasons we have therefore used only one instrument.

Pitch used for the a cappella works is A=440, for the accompanied items A=415.