This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Gregorio Allegri, born in Rome in 1582, trained as a boy chorister under Giovanni Bernardino Nanino before holding a post at the cathedral in Fermo and then returning to Rome. Pope Urban VIII appointed him a singer in the Sistine Chapel choir in 1629, a position Allegri held without interruption until his death there in 1652, placing his entire mature career inside a single institution rather than across the several posts more typical of composers of his generation.
Allegri composed exclusively sacred music, working in a conservative style rooted in the polyphonic achievement of Palestrina rather than in the newer musical currents developing elsewhere in early seventeenth century Italy. That choice of a deliberately older idiom, maintained across a career spent entirely inside the Sistine Chapel's own choir, matched the conservative liturgical setting he served rather than the wider musical experimentation of his own lifetime.
A priest, singer and composer whose documented career runs from a boyhood choir stall under Nanino to more than two decades as a Sistine Chapel singer under successive popes, Allegri built his reputation on sacred vocal writing meant for one specific liturgical institution, the same institution that would go on to define how his most famous work was heard for centuries after his death.