Kelly Clarkson’s second studio effort, “Breakaway,” is that rare exhibition of substance over style. While the majority of today’s hitmakers rely upon gimmicky collaborations and novelty arrangements to court popular appeal, our “Idol” heroine is busting a move to showcase keepsake melodies and vocal prowess to claim her place in the spotlight. Throughout, Clarkson exhibits the ability to dominate some fairly aggressive material (“Behind These Hazel Eyes,” “Gone”). She’s also not afraid to tackle two beautiful ballads, “Because of You” and “Where Is Your Heart,” which will thrill fans. But for the most part, the guitars are amped up here, maintaining universal appeal and a boatload of potential hits to rival Avril Lavigne and the likes of Ashlee Simpson and Lindsay Lohan. Clarkson proves that she’s the real thing, packed with enough potency to ensure radio that she’s here to stay. Here’s a hit female artist who has the chops for lasting success.—CT