Normally, when a major component of a band is hindered by an illness, a concert loses its energy.

That wasn't the case Thursday night when Cowboy Mouth made its annual stop at the Potawatomi Casino / OnMilwaukee.com stage.

Lead guitarist / vocalist John Thomas Griffith was -- for the most part -- silenced with a summer cold. Yet, there was no shortage of electricity as the quartet brought, what it called "kick ass, southern American rock" to the opening night of Summerfest.

The 90-minute set featured a handful of favorites that repeat concertgoers sang along to with gusto. Drummer and lead vocalist Fred LeBlanc -- playing barefoot and clad in a New Orleans Saints jersey, gym shorts and about 10 pounds of sweat -- carried the show, demanding energy from the crowd that met that of the band, which opened with "Love of My Life."

What Griffith lacked in vocal ability Thursday, he made up for with his guitar skills. As OnMilwaukee.com senior editor Drew Olson wrote in his Summerfest picks, nobody opens as strong as Cowboy Mouth. Under the weather or not, Griffith was electric on his guitar and equally intense late in the show when he switched to the keyboard.

Cowboy Mouth shows are, for lack of a better term, predictable -- in a good way. Fans know, for the most part, what songs they're going to hear. While the band is releasing a new CD later this fall, there was little sense of "pimping " the new disc: the newer songs were blended in with the fan favorites; culminating in the finale -- and the band's best-known hit, "Jenny Says."

Considering the frequency of Cowboy Mouth's visits, it's somewhat surprising how many people turn out for their shows. That popularity is a testament to the quality of show the band puts on.

Over the next 10 days, plenty of better-known and higher-profile bands will take the stage at Summerfest. Few of them, however, will be able to match the intensity or provide fans the experience like Cowboy Mouth.