Commercials don’t necessarily mesh with indie rock’s free-spirited autonomy, but just try to argue with their power to propel unknown acts into the mainstream consciousness. It happened for the Dandy Warhols when ”Bohemian Like You” landed in a European cellphone ad campaign. And now, the sinuous organ scratch and cantering beat of ”Jerk It Out” by the Caesars has become a television staple as the theme song for the iPod Shuffle. The high-profile placement could be just what the Swedish quartet needs to expand the small following they’ve already attracted here into the kind of star status they enjoy at home. The instantly recognizable song appears, but slightly remixed, on ”Paper Tigers,” which is their third US release. It’s a smart, beguiling blast of pop-rock that finds the band digging deeper than on previous discs. Album opener ”Spirit” is a mournful rock ballad with elegiac organ, while ”May the Rain” is a mid-tempo lovelorn lament. Buoyant garage rock resurfaces on ”It’s Not the Fall That Counts,” propelled by a catchy chorus and bold Farfisa organ, and ”We Got to Leave,” which recalls the Dandy Warhols with its psychedelic organ, bright hand claps, and luminous harmonies. Now that they’ve snagged our attention, the Caesars deliver a mature but lively blast of classic rock-influenced music with real substance at its core.