The three members of Rascal Flatts sit like reigning kings—in high-backed, throne-like chairs with a red velvet curtain behind them—on the cover of their sixth album. And why not? After 10 years and just as many No. 1 country singles, the trio has long ruled the country world and may well be the "Unstoppable" force the title posits (although the song itself is about love, not career). The 11-track set is unlikely to slow the group's momentum, since it's as polished as a diner countertop. It has the requisite array of country-pop straddling sonics, starting with the soaring choruses and fiddle hooks of "Love Who You Love" through to the chugging rock tempo of "Close" and the arena-sized beat of "Summer Nights," whose power chords and well-worn lyrical images of beach party celebration sound like Kenny Chesney's "Summertime" as played by the Dave Matthews Band. Rascal Flatts and its assorted songwriting cohorts also bring out such heart-wringing, earnest lost love paeans as "Here Comes Goodbye," "Why" and "Forever." —Gary Graff