By Matt Mueller, special to OnMilwaukee.com   Published Jul 06, 2012 at 3:25 AM

Some people would argue that rock is dead, but I, as well as everyone else present at the BMO Harris Pavilion Thursday night, think differently. For those in the packed house, rock isn't dead; it's just been renamed folk and given a twangy, energetic kick by The Avett Brothers.

The North Carolina-based band, a vibrant combination of banjo player Scott Avett, his brother and guitar counterpart Seth and stand-up bassist Bob Crawford, started in 2000 with their self-titled EP. Since then, the group has become one of the premium indie folk rock groups currently making music, perhaps only behind Mumford and Sons in terms of mainstream popularity. In fact, the two groups appeared on last year's Grammy Awards with Bob Dylan, a solid way to get some much-deserved attention.

Understandably, a few readers might be wary of folk music and its ability to rock out. It's often perceived as a more intimate, docile brand of music. In fact, last week, the folk group Nathaniel Rateliff brought their perfect harmonies to the U.S. Cellular Connection Stage to mixed effect. They sounded absolutely terrific, but one can't help feeling that an outdoor stage surrounded by commotion and other acts vying for attention isn't quite the right venue for Rateliff's brand of meditative, mellow folk.

Any worries of The Avett Brothers having similar issues were instantly blasted out the back of the pavilion by their opening two numbers, "Laundry Room" and "I Killed Sally's Lover." Both songs featured the kind of rich harmonies and authentic Southern twang a listener would expect from folk music, but they also brought a rollicking and explosive rock energy that captivated the crowd.

Thankfully, the band didn't sacrifice sound quality in the process (a problem that plagued their spirited opener, Wheeler Brothers). An audience member could clearly hear all of the Avett Brothers' various elements, whether it be the luscious harmonies in "Laundry Room," Seth Avett's raw and compulsively catchy vocals in "Will You Return" or Joe Kwan's cello on "And It Spread."

The balanced audio helped maintain the Avett Brothers' clever songwriting skills. Sometimes their brilliance was just in the delivery, such as the bluegrass-tinged talk verses in "Down With the Shine" and "Slight Figure of Speech." Other times, however, it was the lyrics themselves that made the numbers shine. They showed off a dry wit with "Love Like The Movies" and then one song later, hit the heart with "Salina," a melancholy ode to touring life and leaving home.

The Avett Brothers' music was big (even their acoustic duet combo of "Murder In the City" and "Just a Closer Walk with Thee" filled the pavilion), and their stage presence matched. One of the biggest reasons was Seth Avett, who could be doing an easy-going trot in place for one number and then unleash a ferocious rock star fervor.

Seth, as well as his brother Scott, also bombarded the crowd with compliments and genuine thanks. They really seemed happy to be there, a point made even more apparent by their three-song encore (which included "Shame" and "The Perfect Space"), topping off a completely satisfying two-hour set.

Their only misstep is, quite frankly, more of a personal gripe rather than an actual flaw. At about the early mid-way point of the show, the guys switched out their banjo and stand-up bass for an electric guitar and electric bass. The songs, "Slight Figure of Speech" and "Winter In My Heart," still sounded great and the harmonies were as on-point as the rest of the numbers, but they missed the twangy originality of the songs that came before and after.

This, however, is a miniscule nitpick in a concert that rocked the crowd with its contagious energy and Southern authenticity. Even the balmy temperature inside the pavilion was more of a boon than a detriment, transporting the audience mentally to a soulful folk gig in North Carolina that no one wanted to leave.