Most of the time, songs are going to start on the I (one) or home chord, go to some other chords (the chord progression) and then return home. The tonal center of the song is what you want to establish in your ear. That’s the key to finding your way around the rest of the chords.
By playing along with one chord songs you have eliminated the problem of figuring out a chord progression which leaves you time to really listen to the one and only chord you have in the song. This will give you time to play different inversions of your one chord, figure out the melody, practice soloing over the chord and trying different strumming patterns.
If you know of any other one-chord songs, please drop me a note and let me know the titles so I can add them to the list.
Run Through The Jungle-CCR Key of D (D7)
Get Up, Stand Up-Bob Marley Key of C minor
Electric Avenue-Eddy Grant Key of A