Knockin' on Heaven's Door

The harmonic genius of 'Knockin' on Heaven's Door' lies in its radical economy — just four chords (G, D, Am7, C) arranged in two patterns create one of rock's most emotionally powerful songs. The verse's I-V-ii motion has a descending, fading quality perfect for a dying man's words, while the chorus's I-V-IV provides just enough lift for the repeated refrain without undermining the song's gravity.

Dylan wrote the song specifically for a scene in Sam Peckinpah's Western film 'Pat Garrett and Billy the Kid', in which the character Sheriff Colin Baker (played by Slim Pickens) is fatally shot and dies by a lake while his wife watches. The lyrics directly reference this scene, with the dying lawman addressing his wife as 'Mama'.

Written by Bob Dylan for the 1973 film 'Pat Garrett and Billy the Kid', this sparse meditation on mortality became a worldwide hit and one of Dylan's most enduring post-1960s songs. Its four-chord simplicity has made it irresistible to cover artists from Eric Clapton to Guns N' Roses.