The guitar riff was inspired by Eddie Cochran's "Nervous Breakdown." Jimmy Page used a small, miked amplifier to create the "guitar in a shoebox" sound. Explaining his technique to Guitar Player magazine in 1977, Page said: "I put it in a small room, a tiny vocal booth-type thing and miked it from a distance. You see, there's a very old recording maxim which goes, 'Distance makes depth.' I've used that a hell of a lot on recording techniques with the band generally, not just me. You're always used to them close-miking amps, just putting the microphone in front, but I'd have a mic right out the back, as well, and then balance the two, to get rid of all the phasing problems; because really, you shouldn't have to use an EQ in the studio if the instruments sound right. It should all be done with the microphones. But see, everyone has gotten so carried away with EQ pots that they have forgotten the whole science of microphone placement. There aren't too many guys who know it. I'm sure Les Paul knows a lot; obviously, he must have been well into that, as were all those who produced the early rock records where there were one or two mics in the studio."