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 John Doan playing Harpolyre music by Fernando Sor, "It's Christmas" Harpguitar John Doan, John Doan - Victorian Concert - Harp Guitar and 20 antique stringed instruments