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 Die Walküre: "Wintersturme" -- Jonas Kaufmann (Met Opera), Levine Returns with Così fan tutte, Manon: Act IV Trio excerpt -- Netrebko, Beczala, Szot (Met Opera)