Watch the Open Em Tuning online guitar lesson by Sonny Landreth from Slide Supernatural

E minor tuning is the same as E major tuning but we’re going to drop down the third string from a G sharp down to a G natural, which makes it an E minor chord. That’s nice. So the low string is the big E, and going up to the next string, the fifth, we have a B, just like an E tuning, and we go up to the next string we have an octave E, so there’s your octave there. And then you go up to the third string, brought down a half step and G natural, making it an E minor chord, up to the second string, which is still a B, and the top string which is a high E.  It’s real bluesy too and it gets that modern sound as opposed to the somewhat darker sound of D minor tuning. I also like how the top three strings are the same as standard tuning. That's helpful if you are just getting into slide playing.