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 Jean Sibelius: Novelette for Violin and Piano, Op.102, W.A. Mozart - Sinfonia Concertante-Andante / Igor Oistrakh and Valery Oistrakh (part I), Edward Elgar - La capricieuse Op.17