Domenico Allegri was an Italian composer and singer of the early Baroque Roman School. He was the second son of the Milanese coachman Costantino Allegri, who lived in Rome with his family, and was a younger brother of the more famous Gregorio Allegri. Costantino sent three sons, Gregorio, Domenico and Bartolomeo, to study music at San Luigi dei Francesi, under the maestro di capella Giovanni Bernardino Nanino, brother of Giovanni Maria Nanino. The little boy had as schoolmates his elder brother Gregorio and then Antonio Cifra, Domenico Massenzio and Paolo Agostini.