Former Replacements drummer Chris Mars has a chip on his shoulder that's as big as his talent. Mars wrote all the songs and plays almost every instrument on 75% Less Fat (as he did on his 1992 debut, Horseshoes and Handgrenades), and he makes damn well sure you know it. But it's easy to see why he tries so hard to prove himself. After all, drummers are usually dismissed as the most expendable of...