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 Sonata in F Major - Corelli - MRA Recital II 2013 11 17, Bipperies - No. 2 - French Horn Duet - Micheala Andrews and Michael Brossart