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 Snyderphonics Manta - pizzicato example, Substratum, by Jeff Snyder - performed by Susan Alcorn and the Mivos String Quartet, Manta sequencer / drum machine / bassline