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 Max Reger: Serenade in G Major for Flute, Violin, and Viola, 3rd Movement, Max Reger: Serenade in G Major for Flute, Violin, and Viola, 1st Movement