Q: what is a power chord
A: you know how a major chord has one note different from a minor chord .... well a 'power chord' is when you don't play that note at all. just the 1 and 5. probably has the most 'power' when it's played on guitar with some distortion, in low range with another octave on top. so low E, B, E. or G, D, G. used all the time in distorted guitar music because major/minor intervals start to crap out when the distortion comes on, and also don't work in the low range. 'power chords' seem most at home in a reasonably low range, around the low area of a guitar. not to be confused with 'power cord' which provides electricity for the chord