"Percy's Song" is a song written by Bob Dylan. It was an outtake from October 1963 sessions for Dylan's third album, The Times They Are A-Changin'. It was not officially released until 1985, on the compilation Biograph. In the notes to that album, Dylan credits Paul Clayton for the song's "beautiful melody line." He had played "The Wind and the Rain" to him, a variant of "The Twa Sisters", Child ballad 10.
Dylan wrote the song from the point of view of a narrating character. The song relates the story of a fatal car crash and a subsequent manslaughter conviction and 99-year sentence in Joliet Prison that is handed down to the driver (a friend of the first-person narrator). The narrator goes to ask the sentencing judge to commute his friend's sentence which he considers too harsh. The sentence stands.
The song is also available on The Genuine Bootleg Series: the Third One Now