Just the basics, done beautifully

The fundamental appeal of Olson (who is 47) and Louris (53) together in performance was manifest in their division of labor. Louris played a more lead-guitar role, picking out pretty fills and tasty accents while putting his vocal dynamics to work, layering on high harmonies or going lower.

Olson sang with a steady mid-range grain (not unlike the tone of Arlo Guthrie at a few points) while pacing the songs on his guitar (he took exactly one solo all night, following Louris' on "Say You'll Be Mine," their one co-composition from Olson's 2002 solo album backed by the Creekdippers, December's Child).

The key, of course, is the blend in which the sum is greater than the parts, when Olson's and Louris' voices mesh in the beguiling fashion often associated with brothers: Think the Everlys or, more accurately, the oft-cited country comparison, the Louvin Brothers.

Highlights from the somewhat subdued new album included the Louris-sung "Bicycle," which exhibited subtle vocal shades of another roots-music-loving Minnesotan named Bob Dylan, and the lively "Chamberlain, SD." The latter was preceded by a shout-out to the local crowd at the historic theater.

"Bucks County is home of the Holy Modal Rounders, quite possibly one of the greatest groups of all time, up there with the Byrds, Beatles, and the Stones," Olson said. He was alluding to the fact that Steve Weber and others in the Rounders played together in Bucks County before becoming part of the Greenwich Village folk scene of the early '60s.