As The Mad Caps begin their first song Sunday night to launch the Vegas installment of the new traveling monthly concert known as the Rumble, a whopping 29 people are inside the Aruba Showroom. That number includes the two-man local band, members of both acts scheduled to follow, the bartender, promoters and a smattering of local music journalists. Embarrassing statistics, but Mad Caps frontman Ted Rader doesn’t seem to mind. “The good thing about those bright lights onstage is you can’t see anything,” he says as he towels himself off after the set. “You can pretend there’s a big crowd."

Dismal turnout notwithstanding, Rader and drummer John Bolduc say their crowds have only grown in size since the blues-rock duo began performing roughly a year ago—particularly since the twosome ditched its original, melancholic sound for a cowbell, a tambourine and a more toe-tapping, surfy sound.

The Elvis influence is obvious: His face is printed right on their EP, Rader likes to shake his hips, and The Mad Caps and cover an Elvis song live. But Rader and Bolduc insist something else influenced their newest music: “Gay Bar” by Detroit dance-rock outfit Electric Six. It’s all about having fun, Rader says, precisely what they hope to capture as well.

Still, that doesn’t mean the band doesn’t take itself seriously. “We consider our music to be serious on a level that can include beach balls,” Bolduc says.