Walk into Neon Leon Studios in Nashville, and you’ll see some mismatched chairs, funky spare furnishings — pretty much what you’d expect in any typical band hangout. But Kings Of Leon are hardly typical. Poke around a little more and you’ll find the rehearsal stage, the world-class recording facility … maybe even their three Grammy Awards and various Platinum and Gold certifications. Or maybe not.

Inside, the brothers Followill — lead singer/guitarist Caleb, 34, bassist/keyboardist Jared, 29,  and drummer Nathan, 37, — relax with their cousin, lead guitarist Matthew Followill, 32, a couple of days before previewing their album, WALLS, at Nashville’s Ascend Amphitheater. About 6,500 fans will gather there on the Cumberland River to welcome their…