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 Leonard Bernstein -Serenade after Plato's Symposium Socrates 5, Johannes Brahms, Violin Concerto in D major, Op. 77, part 2 - Adagio, Concerto for Violin, Cello and Orchestra by J. Brahms - 2 andante /2/