Watch the Open A Tuning online guitar lesson by Sonny Landreth from Slide Supernatural
Open A tuning or Spanish tuning is apically the same as open G tuning but everything is up a whole step. From low to high the strings are E, A, E, A, C#, E. I was first turned on to open A tuning by Lowell George and Robert Johnson. I really like the higher tuning of open A because it produces some great upper partials and harmonics that I find extremely useful. Note how different it sounds from open G, I find it has a great lyrical quality to it that leans itself to different songs and melodies. As we saw in open G, we have the same octave combinations between the strings. Experiment playing in both of these tunings to really hear the sonic difference.