After an anticipatory second-by-second DatPiff countdown, Detroit, the latest mixtape from Big Sean, is now available. The project spans 17 tracks and features guest spots from Common, Kendrick Lamar, French Montana, Juicy J, Chris Brown, Tyga, and Snoop Lion (f.k.a. Snoop Dogg), not to mention production from the likes of Young Chop and Lex Luger. And, damn, this thing has already been DL-ed 400,000 times. It just came out. Check below for the free stream and/or download; Cruel Summer, the debut full-length from the Kanye-spearheaded G.O.O.D. Music, on which Sean will appear, is set to debut September 18.