In the dozen-plus years since their breakthrough song, the three Hanson brothers have been trying to live up to and live down “MMMBop.” Their eighth album reaches a compromise. After spending the past decade proving their chops with R&B-style workouts, Isaac, Taylor, and Zac return to the pop that made them famous. But there are also plenty of times on Shout It Out where 27-year-old Taylor belts like a blue-eyed soul man. The best cuts — the piano-driven “Waiting for This,” the rolling “Kiss Me When You Come Home” — split the difference between the group’s ambitions. And “Thinkin’ ’Bout Somethin’” is the most fun they’ve had on record since “MMMBop.” Hanson mostly stays away from the heavy-handed navel-gazing of their last album, 2007’s The Walk, instead filling Shout It Out with the sort of soulful pop that made them teen stars.