Watch the High Root Boogie online guitar lesson by TrueFire from Play Acoustic Guitar 6: Lick Lexicon
High Root Boogie - A Lick 9 is a video guitar lesson presented by David Hamburger and is sourced from Fingerstyle Blues Factory.
This lick is, rhythmically, in a similar vein as A7 Boogie, and this kind of chord shape, where you reach up on the high string to grab a high root, A, takes a bit of getting used to, but it's an effective sound, especially when you use it to go from the root down to the b7 at the third fret. You'll often hear this sound used over E, too. To try it, bar the top three or four strings at the 9th fret, then reach up to the 12th fret on the high string with your pinkie (it's less of a stretch, at that altitude). Move your pinkie down chromatically from the 12th fret, to the 11th and finally the 10th fret (for an E7 voicing) and, with the low E string in the bass, you'll have yet another classic country blues move under your fingers.