Allegri's Miserere

Miserere (full title: Miserere mei, Deus, Latin for "Have mercy on me, O God") is a setting of Psalm 51 (50) by Italian composer Gregorio Allegri. It was composed during the reign of Pope Urban VIII, probably during the 1630s, for use in the Sistine Chapel during matins, as part of the exclusive Tenebrae service on Holy Wednesday and Good Friday of Holy Week.

The Miserere is written for two choirs, one of five and one of four voices, and is an example of Renaissance polyphony. One of the choirs sings a simple version of the original Miserere chant; the other, spatially separated, sings an ornamented commentary on this.

The Tenebrae service where the Miserere would be sung normally began at dusk, hence the name (tenebrae is Latin for "shadows" or "darkness"). During the ritual, candles would be extinguished one by one, save for the last candle which remained alight and was then hidden. Gregorio Allegri envisioned the setting of the Miserere to be the final act within the first lesson of the Tenebrae service.

It was the last of twelve falsobordone Miserere settings composed and chanted at the service since 1514 and is the most popular.

At some point, it became forbidden to transcribe the music and it was allowed to be performed only at those particular services at the Sistine Chapel, thus adding to the mystery surrounding it.

The setting that escaped from the Vatican is actually a conflation of verses set by Allegri around 1638 and Tommaso Bai (also spelled "Baj"; 1650–1718) in 1714.

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