Anglo, Capt Birdseye -- thanks for the thoughts re equal temperament. I always wondered about that -- don't think I've ever heard or played an instrument in 'mean temperament. And even though this is a divergence from that great little blues scale posted above (which is more than worthy of a thread of it's own, sorry bout that), I'm wondering - do digital guitar tuners use "equal temperament" then?

I learned to tune by ear as a kid taking violin lessons. Never owned a tuner for guitar till I got one for Xmas last year. I haven't used it much, except in noisy rooms -- fiddlin around with the thing seems to take me even longer than tuning by ear. And I've noticed that I often have to make a couple tiny 'adjustments' after using the tuner, even when all six strings get the green light.

And I've wondered if that's because the tuner is not in equal temperament, so in any key except C (where there's no #'s or b's) it will sound a little 'off'??

Could be because I need more practice with the tuner, though ....