Open A Tuning (E.A.C#.E.A.E)

Larry Sandberg says that the Open A tuning is especially useful for the "delta blues sound," and it is a great bottleneck tuning, since it's easy to slide from minor to major on the fourth string.

Like most open tunings, it is easy to find alternate chord voicings by taking advantage of the strings that are tuned in octaves. Consider open position A minor 7 chords. The fourth string must be played on the third fret, but any other string can be played either open. or on the third fret. This leads to a wide variety of fingerings.