Gregorio, an ecclesiastic by profession, and a celebrated composer of music of the seventeenth century, was a native of Rome. He was the disciple of Nanini, the intimate friend and contemporary of Palestrina. His abilities as a singer were not remarkable, but he was deemed an excellent master of harmony; and so much respected by all the musical professors of his time, that the pope, in the year 1629, appointed him to be one of the singers of his chapel. To his uncommon merit as a composer of church music, he united an excellent moral character, exhibiting in his actions the devotion and benevolence of his heart. The poor crowded daily to his door, whom he relieved to the utmost of his ability; and not content with these beneficent actions, he daily visited the prisons of Rome, in order to relieve the most deserving and afflicted objects which were immured in these dreary mansions. With such divine simplicity and purity of harmony, did he compose many parts of the church service, that his loss was severely felt and sincerely lamented by the whole college of singers in the papal service. He died Feb. 18, 1650, and was interred in the Chiesa Nuova, in a vault destined for the reception of deceased singers in the pope's chapel, before the chapel of S. Filippo Neri, near the altar of annunciation.

Among his other musical works preserved in the pontifical chapel, is the celebrated miserere, which, for 170 years, has been annually performed at that chapel on Wednesday and Good Friday, in Passion week, by the choral band, and the best singers in Italy. It is, however, generally believed, that it owes its reputation more to the manner in which it is performed, than to the composition itself. The beauty and effect of the music is not discernible upon paper, but the singers have, by tradition, certain customs, expressions, and graces of convention, which produce wonderful effects. Some of the effects produced may be justly attributed to the time, the place, and the solemnity of the ceremonials observed during the performance. "The pope and conclave are all prostrated on the ground, the candles of the chapel and the torches of the ballustrade are extinguished one by one, and the last verse of this psalm is terminated by two choirs; the maestra di cappello beating time slower and slower, and the singers diminishing, or rather extinguishing the harmony-by little and little, to a perfect point." Padre Martini says, that there was never more than three copies made by authority, "one of which was for the emperor Leopold, one for the late king of Portugal, and the other for himself: but a very complete one was presented by the pope himself to King George III. as an inestimable curiosity." (Gen. Biog.)