When Clap Your Hands Say Yeah achieved surprising popularity from the release of their 2005 self-titled debut, it wasn’t from some huge major-label deal (or the smothering mass marketing that inevitably follows). Sure, the incredible amount of Internet word-of-mouth helped considerably, but it was something else altogether that sold six figure’s worth of copies.

The reason? Clap Your Hands Say Yeah had real, honest-to-goodness songs to back up the hype. Bouncy, energetic rhythms, deliciously bright choruses and the throaty, slippery David Byrne-cum-Jeff Mangum-cum-Dan Bejar timbre of front man Alec Ounsworth sprinkled the album and built a gorgeous swirl of shaggy, luxurious pop rock that sent chills down spines. It certainly was not the be-all, end-all “best indie record ever” so many blogged it to be, but it was a fantastic start.

Once they proved they could deliver what people wanted, then came the pressure to be consistent. But CYHSY’s latest “Some Loud Thunder” is a rebellion against such a notion – an obvious effort on the band’s part to branch out, to re-flex their creative muscles after the often-bruising jabs of too much publicity. The title alone says it all, suggesting perhaps the real racket they hope to make this time around: the towering cacophony of darker, heavier tracks commandingly booming enough to be distinguished well above the swarming buzz.

Sometimes, however, over-experimentation can be a plague, and is most often the cause of the once-great delivering the dreaded Sophomore Slump. “Some Loud Thunder” isn’t quite a crash-and-burn – it contains several bold, euphoric moments, but also has lots of desolate duds to match. Ultimately, the results are high on effort and style, but often fairly low in substance.

The opening track, “Some Loud Thunder,” could have been pretty flawless. The tambourine-blessed beat is infectious, the guitars are awash with a jangling, ’60s pop feel, and Ounsworth works his unique set of pipes to the fullest. Then, for some reason, CYHSY decided to mask all of these sumptuous elements in confusing, awful distortion and hollow vocal filtering that sounds more like a poorly recorded CD rip than edgy artistic integrity. Why? Who knows. But lyrics like “Yes, that was me breaking glass/ and pretending to start something big/ some new taste” probably offer an explanation.

The truly engaging moments that follow are those that borrow most from their sounds of old – songs that would be right at home on CYHSY’s debut. “Mama, Won’t You Keep Them Castles In The Air & Burning?” and “Underwater (You & Me)” are vintage-tinged garage gems that start psychedelically dreamy and push forward into energetically triumphant territory. “Satan Said Dance” is an admittedly silly but nevertheless enjoyable freak-out set in a hell where constant dance is the devil’s punishment: “He says to me to shake around/don’t stop until you’re in the ground/Satan, Satan, Satan said DANCE/let’s dance!”

Darker, slower songs interrupt the feel-good flow of the album’s more propulsive foot-stompers. Some build and then fizzle, like the unnecessary minute-long accordion ballad “Upon Encountering The Crippled Elephant” and its dragging, plunking predecessor “Goodbye To The Mother & The Cover.”

Others make it work in their favor, like the elegant, painstaking first single “Love Song No. 7,” which boasts woozy, well-layered harmonies, a torch song-type piano and Ounsworth’s shaky attempts at reassuring himself that he’s “safe and sound/ safe for now.” It’s a fine, but unfortunately rare, example of one of the album’s experimentations working in the band’s favor.

Mostly, it is an album slightly bogged down by its over-employment of difficult, off-putting sounds and concepts, though “Some Loud Thunder” uncovers a unique richness in the songs CYHSY don’t leave for dead. It is hoped the band has a long future ahead of them even despite their ever-so-slight slump, and thus plenty of practice in learning to choose the usual good ideas over the plain, useless ones.