Gregorio Allegri (c. 1582 – 1652) was an Italian composer of the late Renaissance, best known for his sacred choral music. He was associated with the papal choir at the Vatican, where he served as a priest and musician. Allegri's most notable work is the "Miserere," a setting of Psalm 51, which became famous for its intricate counterpoint and the use of a high soprano voice. The piece was composed for the Holy Week liturgy and was famously protected by the Vatican, with strict penalties for anyone who attempted to transcribe it. Allegri's "Miserere" gained widespread acclaim in the 18th century, particularly after being transcribed by Mozart, who famously heard it during a visit to Rome and wrote it down from memory. This act helped to popularize the piece beyond its original context, influencing the development of choral music and inspiring many composers. His contributions to music are significant in the transition from the Renaissance to the Baroque era, showcasing early examples of expressive harmony and text setting. Allegri's work continues to be performed and studied, marking him as a key figure in the history of Western choral music.