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 Lucky (ukulele cover; original by Jason Mraz & Colbie Caillat), "Santa Claus is Coming to Town" ...ukulele style!, Music & Me - Michael Jackson Ukulele Tribute