IMO, Casey's primary contribution is to us Haley's fans. He has shown Haley that it's OK to show more of herself, and have fun doing it.
Everything Haley needs, musically, is already engrained in her from Birth, she's been absorbing music history through her parents, on so many levels. All she needs to be a performer, she's already got the tools for. She's been primed to be musically talented as long as she's remembered
I've always had the sense that Haley, in the end, is a very private person. If it wasn't for Casey showing Haley that it could actually be fun, that you could have a good time, he shows her by having fun himself, invites her to join him, unlocks sides of her personality that she might not otherwise show, we wouldn't have the Haley we know and love now
That's where I give Casey the most credit. Two insanely talented musicians, one has shown the other that music and performing can also be wild, wacky and fun
