You know, play the harmonic of the low E string at the 5th fret and match that tone with the harmonic of the A string at the 7th fret and so on (with the exception of the B string.)
I can. I don't mean to brag, but it's like second nature to me, but I don't have the ability to tune the low E string to exactly E without making a comparison to an external E tone first, though.
It bugs me sometimes to jam with people who can't tune by ear using relative harmonics, then when they try to use a sub-par tuner it's still obviously out of tune, and then they try to do it the fret-pressing way and it's still out of tune, and then when I offer to tune it for them they ferociously decline because their ego would explode. And then the actual jam is actual ####.
Anyways, can you do it? Have you tried? I have friends who understand the theory (supposedly) but can't under any circumstances actually show that they know how the harmonic beats work in conjunction with eachother in order to produce two unison tones if properly tuned.
