The difference live is that the albums’ bombast works much better when the group is cranking it out onstage in front of thousands of cheering fans. In the loosest sense, Rascal Flatts is a country band, but its penchant for rock ’n’ roll is undeniable, and the proof is in its crossover success on the pop charts.

Songs like “Bob That Head,’’ “What Hurts the Most,’’ and “Me and My Gang,’’ all of which were hijacked by serenading fans at the Comcast Center, would have been hits in any genre.

For all the volume and theatrics, though, some of Rascal Flatts’s shining moments were the dialed-down ones. “Bless the Broken Road,’’ a beatific ballad with gospel overtones, showcased the group’s tight three-part harmonies. And guitarist Joe Don Rooney and bassist Jay DeMarcus snatched their own bit of the spotlight with a more intimate segment meant to emulate some Nashville front-porch singing and picking. Playing piano, DeMarcus led the crowd in a medley that included “Lean on Me’’ and “Backwards.’’