"The Musical Box" is a song by English progressive rock band Genesis, which was originally released on their third studio album Nursery Cryme in 1971. The song is written in the key of F# major.

Though credited solely to Banks/Collins/Gabriel/Hackett/Rutherford, "The Musical Box" began as an instrumental piece written by Anthony Phillips called "F#" (later released as "Manipulation" on the Box Set remaster). The lyrics are based on a Victorian fairy story written by Gabriel, about two children in a country house. The girl, Cynthia, kills the boy, Henry, by cleaving his head off with a croquet mallet. She later discovers Henry's musical box. When she opens it, "Old King Cole" plays, and Henry returns as a spirit, but starts aging very quickly. This causes him to experience a lifetime's sexual desire in a few moments, and he tries to persuade Cynthia to have sexual intercourse with him. However, the noise causes his nurse to arrive, and she throws the musical box at him, destroying them both. The album cover shows Cynthia holding a croquet mallet, with a few heads lying on the ground.

Collins unusually uses mallets on his drums during the flute solo and Gabriel also plays oboe during the 'Old King Cole' section. Hackett, Banks and Rutherford all play 12-string acoustic guitars. Mick Barnard added guitar parts towards the end of the song during his brief tenure with the band when they would rehearse it that the band liked. Hackett kept both the guitar parts from Phillips and Barnard, while adding his own pieces to the song as well.

In live performances, Peter Gabriel would wear an "old man" mask for the final verse and unzip the chest part of his black jumpsuit. Dramatic lighting would be used each time he shouted "NOW!", "The Musical Box" was featured in their live repertoire right up to Phil Collins' departure after the We Can't Dance tour in 1992, albeit with only the closing section being included as part of a medley.

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