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 Beethoven - Sonata no. 23 in F minor, op. 57 ("Appassionata") - Anna Fedorova, Paderewski - Menuet and Nocturne - Eduard Kunz