Unlike the massive polychoral compositions of the Venetian School, in which performance groupings were positioned in lofts across from each other in a large space, the choirs in "Missa sopra Ecco sì beato giorno" were probably not meant to be significantly spatially separated. Although Striggio left no performance directions, the most likely arrangement was for the singers to be positioned in a large semicircle, with the instrumentalists in its center, in view of the singers. The exact instruments used, and their number, is not known, but probably varied from performance to performance. An unusual feature of the mass is the existence of two partbooks for a "Bassus ad organum", a part which doubles the composite bass line of the entire composition. Presumably Striggio used this as a compositional tool, to keep track of the harmonies as he wrote forty to sixty voice parts above it; it also foreshadowed the development of the basso continuo in the 17th century.