The choral piece that earned Mozart a Papal honor
aleteia.org
"Miserere Mei, Deus" was forbidden to be copied or distrubuted. That is, until Mozart transcribed the whole piece from memory and gave it to a publisher.
The original post: /r/todayilearned by /u/BiggieTwiggy1two3 on 2024-12-18 01:10:14.

Original Title: TIL that in 1770, 14-year-old Mozart attended a Vatican performance of Allegri’s Miserere, a choral piece so sacred its sheet music was kept secret under penalty of excommunication. He memorized it in one hearing, transcribed it, and helped bring it to the public.