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 - Brandenburg Concerto #4 - Solo Violin, Two Solo Flutes, Strings & Continuo, Virgil Thomson - Serenade for Flute and Violin, Max Reger - Serenade in G Major for Flute, Violin and Viola, opus 141a