This Clash classic just uses 4 chords - D, G, A and F major. It's a good song to learn because the timing is tight, with pauses in the verses. This forces you to develop your own internal metronome. The chord changes are quick so you need to work at that too. Because the riffs are highly repetitive, you can learn the song parts quickly, and know the whole song in no time!
There are 2 guitars for the song, and they play the exact same thing except for the choruses. Here we look at the 1st guitar, which is the easiest (and more fun) to play. For Guitar 2 instead - click here.
Intro / Verses:
D maj - G maj - D maj (repeat)
Easy stuff, just use constant down / up strums.
Other riffs are the occasional G maj - F maj - slide to - G maj
and...
A maj - A7
The Chorus is also easy chords. It's really just a faster / extended version of the verse chord progression above. You'll need to switch between chords quickly and watch the strumming. It's down / down - up / up - down (repeat):
D maj - G maj - D maj (repeat)
G maj - F maj - slide to - G maj
repeat the first part once more, and (again)...
A7
Remember to get it right slowly first. Make sure you can switch between chords smoothly (e.g. the D maj - G maj - D maj of the intro). Once you can do the finger changes without uncomfortable gaps between the different chords, work on speeding everything up. Use the Core Skills on Strumming section for more info on chord switching if you get stuck!