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 Ukulelezaza plays solo - "Under Paris Skies" - George Formby Spring Convention 2013, Sam Brown's Ukulele Club of Sonning Common play "Ace of Spades", Black Eyes