John Sebastian & David Grisman

John Sebastian is a maladroit sellout. With the Lovin’ Spoonful, this stalwart of the early-’60s folk revival morphed jug-band music into the slickest candy imaginable (has a year gone by without a film trailer featuring “Do You Believe in Magic”?). His biggest solo hit was the theme song to Welcome Back, Kotter.

Yet Sebastian’s smooth, straightforward singing—which avoided channeling elderly bluesmen—and the sublime craftsmanship of “Did You Ever Have to Make Up Your Mind,” “Nashville Cats” and, yes, “Welcome Back” made for timeless recordings that transcend wacky movie montages.

Since the early ’90s, the guitarist/harmonicist/autoharpist has been recording traditional music. This tour supports 2007’s Satisfied, Sebastian’s reunion with pre-Spoonful bandmate David Grisman. Though that album’s subdued folk-blues sounds pleasant, Grismaniacs know it’s no challenge for a mandolin master who’s spent 40 years pondering whether his instrument is a traditional bluegrass tool, a jazz guitar, a psychedelic rock gadget or a Middle Eastern oud.

Perhaps this venue can free the old friends from that recording’s limitations. At Old Town, folk-rock legends need not re-create their mainstream hits as they would on the oldies circuit. Which serves Sebastian well, as his shopworn voice is incapable of re-creating his classics. Still, the fragility and hints of mortality in his imperfect vocals heighten his songs’ humanity. This sublime fallibility imbues Sebastian with rustic integrity, even as his website boasts of his tunes popping up in commercials for Vanilla Coke, Gatorade and Pepsi-Cola.

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