By the end of 2008’s 4th quarter, all of G.O.O.D. Music’s “Big Three” will have released albums; John Legend‘s Evolver is available now, Kanye West‘s 808s & Heartbreak drops November 25, and Common‘s Universal Mind Control brings up the rear with a December 9 release date. After the triple blast, however, fellow Chicago native GLC will step up to the plate and drop his debut. To get folks ready, GLC has released a prequel mixtape, named after one of his more frequently-played buzz singles (and one of my very first written blurbs), I Ain’t Even On Yet. Featured on the project is the West-produced Heaven, which reminds us that since this world isn’t perfect, it’s best to aim for a place that is. DJBooth was in attendance at GLC’s listening party on Monday evening and will feature a full-length interview with the emcee in the coming weeks.