videos in AudioSet
A list of about a million ten-second YouTube clips, each labelled with the sounds in it, that Google published in 2017. Labs use it to train and test general audio and music models.
Including J.S. Bach: Aria variata BWV 989 (transcription Sirocco), E. Krähmer (1795-1837): Romance et Rondeau op. 30 (1/2) pour csakan et pianoforte