The crowd that saw Back Door Slam Davy Knowles and Back Door Slam execute an acrobatic set at the Birchmere last night probably hadn’t seen guitar mastery like that since they were Davy Knowles’s age.

The audience skewed middle-aged—I was probably the youngest person there apart from the 22-year-old Knowles himself—and didn’t fill up the entire hall, which was too bad. But that didn’t stop Davy from turning on the electricity and sending portions of the crowd (one exuberant “young” lady in particular) to fits of hooting and flailing with his vintage blues howl and exceptionally lithe digits.

Opener Rob Drabkin, who flew all the way from Colorado for the occasion, was another technical whiz. He played a brief opening set, crooning over some complex acoustic licks in a style that a little too Dave Matthews for my taste. Then came Davy and BDS, and things got loud. Several thousand sixteenth notes, trills, and string-bends later, the show culminated in a slow jam in which Knowles good-naturedly schooled Maryland guitar-maker Paul Reed Smith, who in turn awarded Knowles a $30,000 guitar.

There is little else that can be said of a performance like last night’s—a fact that both acknowledges its brilliance and betrays its limitations. In a way, watching Knowles and his bandmates (especially Ty Bailie, who matched Knowles solo-for-solo on keys) was like watching Cirque de Soleil: amazing at first, but after an hour or so your senses begin to adjust; and the uncommon feats you witness, while still thoroughly enjoyable, seem increasingly routine. The band’s songs were good, but—apart from a ballad here and a throwback slide piece on a resonator guitar there—more or less of a uniform type and tempo. To put it another way, what made last night’s show great was not the songs themselves, but the way they were played.