Watch the Open A Tuning online guitar lesson by Andy Aledort from 30 Beginner Slide Blues Guitar Licks You MUST Know
Along with the open E tuning structure, the next most common open tuning to use with a slide is the open A structure of tuning. The standard open A tuning used for slide is, low to high, E A E A C# E. The sixth, fifth, and first strings are tuned normally, and the fourth, third, and second strings are all tuned one whole step higher than normal. Strumming across all of the open strings yields the sound of an A major chord, and, akin to open E, one can simply lay a fretting finger across all of the strings at any given fret to sound a major chord. For example, laying a finger across all of the strings at the third fret yields a C major chord, barring across the fifth fret yields a D major chord, and barring across the strings at the seventh fret yields an E major chord, etc. Therein lies the beauty and simplicity of open tunings in regard to using a slide: when laying the slide across multiple strings, one can choose to sound a single string or groups of strings and most often the result will be a pleasing and useful sound.