"Why not? We're among friends."

Trampled by Turtles frontman Dave Simonett made that assessment midway through Saturday's love-in at First Avenue, when he and his string-picking/slamming bandmates contemplated playing an instrumental jam that mandolinist Erik Berry had only just introduced to them backstage. The tune is so new it doesn't yet have a name. They played it, of course, and the happy-dancing crowd ate it up. Not only did that moment reiterate how TBT shows have maintained their friendly, informal, house-party vibe even as the Duluth-reared quintet has ascended to selling out two sold-out shows at First Ave. It also proved how well-oiled the Turtles themselves have gotten in that time to pull off such a (semi-cocky) stunt.

The fellas proved the latter point throughout Saturday's nearly two-hour show. You need to be cocksure but also well aware of true greatness to incorporate the four institutional cover songs they pulled off, all tunes you could add to any "100 Best Songs of All Time" list: Gordon Lightfoot's "Sundown" early on in the show (which segued beautifully into the band's own "Victory"), followed later by Leonard Cohen's "Bird on a Wire," then the Faces' "Ooh La La" in the first encore and Dylan's "Don't Think Twice, It's All Right" in the second, with banjoist Dave Carroll or bassist Tim Saxhaug capably taking over vocal duties in most cases.

Of course, plenty of TBT's own tunes were welcomed like classics by the 1,500 fans, who immediately sparked up their giddy dance routines during the opener "Silver and Gold" (the downside of the band's success at First Ave is the lack of dancefloor space). They saved "Wait so Long" for the pre-encore finale, and I'm not exaggerating when I say it went down like "Livin' on a Prayer" at a Bon Jovi concert. Other standouts, in order on the set list, included "Empire" (with a stunning solo by fiddler Ryan Young), the fun but miserable "Drinking in the Morning," "It's a War," the countryfied "Stranger" and the bluesy dirge "Gasoline." My personal favorite, however, came at the end of the first encore, when the tempo downshifted sharply to the slow, so-painful-you-can-feel-it show-stopper "Bloodshot Eyes," one of Simonett's pinnacle moments as a songwriter.

The second encore ended on an up-tempo high with "Codeine," which the guys hammered out so hard Saxhaug broke the top string on his bass near the end. Simonett then laughingly broke off one of his strings in a show of camaraderie. That's probably about as Trampled by Turtles will ever get to a Who-style instrument-crashing finale.