YouTube and listened to them.

The vocalist is Brent Smith. Of a lot of rockers I've heard, his voice sounds to me like one of the better ones. Solidly on pitch and he can back off and sing softly when he wants to (which a lot of rock singers can't), and when he belts, most of the time it looks and sounds to me that he's using good breath support. That saves a lot of wear and tear on the vocal mechanism. But—a lot of the time when he belts, he puts a rasp in his voice—a gravelly sound—and that's darned hard on the vocal cords. Could lead to irritation, laryngitis, and eventually nodes (lumps) on the vocal cords, and finally, loss of voice entirely.

One really good thing about his singing is that, unlike a whole lot of rock singers, he enunciates clearly. You can hear the words.

It's good that you're taking voice lessons, but I hope it's with a live teacher, not just picking it up off a DVD. You need someone who knows what to listen for to listen to you to make sure you're on track. It's hard to judge this by yourself.

But I'd be really careful about trying to emulate Brent Smith, particularly the rasp, for two reasons:   first, sooner or later, that "gravel" will ruin your voice;   and second, if you try to imitate someone's style of singing, you may miss what real potential your own voice has.

Good luck!!

Don Firth