Switching controllers in Guitar Hero 3

I don't know you would have to turn off the guitar then turn on the controller. But why would you want to do this?

 

Also, another guitar hero question... how do I activate star power on a regular controller?

 

I believe you activate it with "A", but I have no idea.

 

You activate star power on a normal controller by pressing back.

 

I have the same problem. My brother and I are one song away from beating the game on hard. We need to beat Once and the last part is impossible with a controller. I need to borrow a guitar hero guitar from one of my friends and beat the song so I can get my achievement for it lol