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 CASIO Privia Pro Stage Piano - PX-5S Demo - part 2, CASIO MZ-X500 Music Arranger sound demo, CASIO MZ-X300 music arranger sound demo