Motet for SATTB, SAAB (SSAATTBB required)
Vatican MS 203 contains Tommaso Bai's setting, unadorned, shortly after its composition, and was scribed by Thomas Altavilla in 1713, who cites Hieronimo Bigello as Master of the Papal Chapel at that time. Bai's setting of the same text is based upon Allegri's, being harmonically similar in its structure. However, there is more variation and harmonic elaboration, with each verse showing differences. The piece is written for the same voices as Allegri's original, SATTB & SSAB, but is more 'modern' than Allegri's slightly archaic setting. All speech rhythm has been removed, and the work takes a more chordal nature with underlying polyphonic movement. The speech rhythm is consistent with that used later for Allegri's. The last half verse, tunc imponent, becomes an antiphonal double choir of SSAATTBB, but again holds Allegri's original structure within it. This setting is, however, not interchangeable with Allegri's original nor any of the subsequent versions.