video 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 草笛演奏「心の窓にともし灯を」 Leaf Whistle "Kokoro no Mado ni Tomosibi wo(Put the light at the window of the heart)"