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 Por Una Cabeza - Pierce Wang, violin, Pre-College Student William Copeland Performs Bach's Gavotte en Rondeau from Violin Partita No. 3, Konpeito Cello Quartet - The Path of Wind