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 J P Sweelinck Fantasia à 4 Echo d4 SwWV261, Johannes Brahms - Chorale prelude Opus 122, #8 "Es ist ein Ros' entsprungen", Pachelbel Toccata in G minor ("Serendipity") POP 283