The Peavey auto-tune guitar thread got me wondering. When I tune a guitar, I only tune the low E-string up using a tuner, and I tune the rest of the strings to it using harmonics and octaves. If I use a tuner all the way through, power chords sound just slightly out-of-tune and dissonant. I don't think it's my intonation because every guitar I've ever played was like this, and I assume it's due to the slight inaccuracy in our modern 12 tone equal temperament system. I recall EVH saying something about how guitars just aren't built right and the B string is out of tune if "properly" tuned, so he slightly flattens it to make chords sound better. I'll do this if playing some Van Halen, otherwise I just make sure it's in-tune relative to the D string using octaves. And so I wondered how auto-tuning guitars deal with this since I've never tried one before. Has anyone else noticed these minor tuning imperfections? How do you tune up and deal with them? I've got a system that seems to work for my style of playing, just wondering if I'm crazy or if this is a common thing. By the way I may have the gift of perfect pitch. I always ear-tune my guitar after putting new strings on it and I'm usually within half a semitone of "proper" tuning, often just a hair flat.