“Knockin’ in Heavens Door” is a wonderful song by Bob Dylan (writer+singer) for the film Pat Garrett and Billy the Kid. It reached No. 12 on the Billboard Hot 100 singles chart.
The song consists of four chords in the key of G major: G, D, Am7, and C. The basic pattern throughout the song is G-D-Am7-Am7 and then G-D-C-C, and this is repeated. There are uncountable covera of the song.
Here’s a man covering the song playing guitar, harmonica, drum and singing as well. He’s a one man band….