Guitar Hero World Tour

To unlock all of the guitars you will need to get five stars on every song while completing every gig (even the ones you must purchase to play) in the Guitar Career on any difficulty. After you finish specific gigs the game will reward you with new guitars which enables them to be purchased as well in the Edit Rocker screen.

After you get five stars on every song and finish every gig, you may need to complete a random song or gig in another career before this will unlock.