I can't remember who pointed this out to me originally, or I credit the tipper effusively. Anyhow, this is a Japanese ad for a Sharp telephone. In this ad, a brilliant Japanese production team assembled a gravity marimba that plays the tenth movement of Bach’s Herz und Mund und Tat und Leben, usually called Jesu, Joy of Men's Desiring in English.
It's mesmerizing. The video's only three minutes long. Check it out.