I'm not a big fan of Buddy Holly's "Peggy Sue," preferring the bigger beat of "Rave On" or the tamped-down sweetness of "Every Day" (more on that one later, perhaps--a deceptively simple-sounding, childlike song with a surprising set of chords in the bridge). But it does have a startling chord change plunked down in the middle, and you can actually see Buddy finger it at about the 1:38 mark. The song's in A...and then he throws in an F, a minor sixth of the tonic:
That's nice and ear-bending, and you might think unique. But then I remembered Carl Perkins' "Honey Don't," which uses the same odd change in its verse. The first instance starts at 12 seconds, wrenching from the song's key of E to a C:
I don't know what it is about early rock 'n' rollers and this I-vi change, but obviously they felt this was a great way to spice up the standard country/blues recipe. It's a little stark for my tastes; to get a similar lift or jolt, I kind of prefer the more gospel-y choice of going from the tonic to a major sixth (sometimes with the V chord between the two, as in "I Wanna Hold Your Hand"), or going from the tonic to a major third (Radiohead's "Creep," "Hey Ya").