Debussy — Clair de Lune with Rain Sounds

Debussy wrote "Clair de Lune" as the third movement of the Suite bergamasque, drafted around 1890 when he was in his late twenties, and did not let it be published until 1905 — by which point he had reportedly lost patience with the whole suite. It has since become the most recognisable piece of French piano music there is, and film has raided it for a century: whenever a director wants moonlight and regret in the same shot, this is what plays.

The performance is by the channel's own pianist, who explains in the description that she put daisies in the thumbnail because of her name — the kind of detail no algorithm produces. Rain runs underneath the full three hours. This is the second most-watched video in the entire catalogue here, behind only Animal Crossing, and the reason is not complicated: almost nobody dislikes this piece, and rain covers the seams.