Gregorio Allegri was a singer and composer at the cathedrals of Fermo and Tivoli and later maestro di cappella of Spirito in Sassia, Rome, and a singer in the papal choir. He composed many of his works for this choir and that of S Maria in Vallicella.

Allegri's reputation rests on his Miserere, a psalm setting traditionally sung every Holy Week by the papal choir. This is basically a simple five-part chant, transformed by interpolated ornamented passages for a four-part solo choir which reaches top C (rare at that time). These passages were a closely guarded secret for many years: Mozart wrote out the work from memory when he was 14.

Allegri was at his best in the a cappella style, as in his five masses, he also published three books of more up-to-date small-scale concertato church music.