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 How to play the 5-Chord Zither demonstrated by Etienne de Lavaulx, German Zither Music, "Let It Be" played by Etienne de Lavaulx on a 5 Chord Zither