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 Acoustic Guitar Notes Tutorial - Korobeiniki - Theme A - Tetris (Sheet music - Guitar chords), Clarinet & Guitar Duet - OMFG - Hello (Sheet music - Guitar chords), Clarinet & Guitar Duet - Star Wars - Main Title (Sheet music - Guitar chords)