The Decemberists' Colin Meloy is much more of a rock 'n' roll frontman than his lawyerly wardrobe or his Clark Kent-model bifocals would ever allow you to believe. And despite his starched white shirt and his buttoned-up vest, Meloy can lead a sing-a-long, engage in witty banter and even make a packed - but not too packed - Pioneer Park audience take a seat on the lawn.

The show - with a crowd somewhere in the relatively manageable 35,000 range - was a pleasant blast of energetic folk-rock that was likely a real treat for people with a strong knowledge of the Oregon indie band's wordy, and well-crafted songbook. For people who are relative newcomers to the group, it was likely a tougher evening to love, thanks to the large amount of beer-swilling show talkers who were out in full force to enjoy the warm summer night and have long, loud conversations with their buddies.

Starting at 8:30 p.m. after a fairly fun 45-minute gig by the 11-person folk-rock ensemble of Typhoon, The Decemberists opened with "Apology Song," Meloy's funny tale about losing a friend's bike. If that doesn't sound like the most rocking song subject ever, well, it ain't. But The Decemberists are still a fun band, even if they're a bit odd. But no more odd than having a frontman who looks like a bearded version of Gregory Peck, a la Atticus Finch in "To Kill A Mockingbird."

But that's part of the charm. And what other rocker decides to use his microphone-granted powers to implore a crowd to take a seat, as he did during the first encore, which segued into "Smoke on the Water," and "Train Kept A-Rollin'. (And no, I'm not making that up.)

Other highlights of the 100-minute set included "Why We Fight," and "Down By The Water."

The down side? The mosh pits down front were a bit intense at times and more than a little annoying as the majority of folks in front of the mixing board were there to hear the music, not get jostled and mauled.

But that's quibbling, the bottom line is it was a fun night with quite a bit of actual rock 'n' roll inside Pioneer.

And what's a review without one final quibble? The posted signs say no smoking, but nobody's reading them and nobody's enforcing them either. A tad surprising, and more than a tad irksome.

Follow Salt Lake Magazine arts/entertainment writer Scott Murphy on Twitter @murphyinfo.