Since the split between front-man Ian Anderson and lead guitarist Martin Barre, both musicians have been steadily touring under an amorphous Jethro Tull banner. Barre, one of the most under-rated and over-looked progressive rock guitarists, is absolutely brilliant when it comes to revitalizing the classic Tull material he helped create. Much like another British Rock stand-out, vocalist Robert Plant, Barre, in the midst of his hard-rocking set, does an acoustic almost-Americana mini-set with different musicians, including gorgeous female vocalists in twin harmony, singing beloved Tull tunes in a wholly new—and lovely—format. Then he goes back to blowing your mind with his stinging leads. Longtime Tull fans are starting to realize that this is, indeed, the essence of Tull. Debonair Music Hall, Dec. 20. Teaneck, NJ.