Gregorio Allegri – “Miserere mei, Deus”

No day like today to reflect on the enormities of mankind, the number and scope of which have, incredibly, survived centuries of prayer. The piece itself (I have learned) was forbidden to be performed outside the Vatican or transcribed, on pain of excommunication. It was only after a 14-year-old Mozart memorized it during attendance and copied it out from memory that it escaped the confines of the Sistine Chapel; the Pope himself praised Mozart and the music was released for general performance.