makes you feel like a rock star ♪ >> reporter: and so he's on the road this summer with his old buddy tim mcgraw yet, there is the uneasy sense that even with all the fame, the money and his famously laid back image, there is still something he's looking for. what do you want that you don't have? >> hmm. i don't know. i -- i'm never content, i don't think. >> reporter: an unquiet soul. >> you know how a shark always moves. i feel that way. >> reporter: that's going to shock a lot of people. >> maybe. there is a part of me that starts to wonder what i'm missing out on. ♪ >> reporter: perhaps it's that sense of longing, of dreams not yet totally fulfilled that makes him so appealing to so many. somewhere with you. ♪ somewhere with you >> reporter: for "nightline," sit cynthia mcfadden in nashville. >> kenny's new album "welcome to the fish bowl" is the in stores