Here’s a classic riff that’s super easy to play. Seven Nation Army by The White Stripes. I’ve done it in the key of A and on acoustic. The song is originally done in the key of E and also Jack White tunes his guitar to an open tuning (open A, I think?). Watch “It Might Get Loud” and he breaks it down in that video.
Yours truly! Will Ripley (Campfire Guitar Star)