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 Sons of the Delta - Crying down in Clarksdale (Mark Cole), Edward Elgar - Introduction and Allegro for Strings pt 1 - Carducci String Quartet, Breabach - encore - Cheltenham Folk Festival 2009