This is the rhythm guitar part for this famous Johnny Cash song. The song is actually played using a capo on the 1st fret, but to keep it easier and save you re-tuning we've done it all in standard tuning. To match the original song, just place a capo on the 1st fret and play everything shown here (1 fret up).
The lead guitar part has been excluded so you can concentrate on the rhythm chords easier. We'll be looking at the lead guitar next.
The chords are straightforward. But notice that sometimes they are partially strummed (some strings are omitted). Use thumb-muting to exclude unwanted strings if you prefer.
The strumming pattern is simple and repetitive, but fast. Watch the ActionTab and get a feel for the strumming. The majority of the song is repetitive down - up - down strums.
The song uses 7 chords:
The chord changes can be tricky, particularly the B7 chord. This is often a chord that causes problems for beginners. The trick to doing it is to arch your fingers from a higher angle than normal. This prevents accidental muting of adjacent strings - particularly the open B string.
As for getting the changes fast - that is always a question of practice. The strumming hand should be able to get the rhythm fairly quickly. This is good, it means you can concentrate more on getting those chord changes smooth.
As always, work slowly and get it right at a comfortable speed. It doesn't matter how slow. Just as long as the changes are smooth. Then work on building speed. Your muscle memory will develop and your fingers will start to find their way much quicker as you practice.