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 Old Roman chant - Terra Tremuit, Byzantine chant - Εγκώμια Αγίας και Μεγάλης Παρασκευής, Chant of Corsica - Tantum ergo