Even the best musicians need a shakeup or challenge every now and then, and Milwaukee’s annual All Messed Up event provides them with a doozy: 64 local players are randomly paired together to create 16 new bands that have three months to create and rehearse about 20 minutes of material, including at least one cover. The resulting bands can be pretty jumbled—by luck of the draw, one could have three bassists and no drummer, for instance—but many of them are able to make hay of what they’re given, and a few have even spun off into permanent projects. The Frankenstein bands created by the latest All Messed Up draw will perform this weekend at a two-night showcase at Linneman’s Riverwest Inn, Feb. 1 and 2. Will any of them be any good? Maybe, maybe not, but the $3 cover each night makes it a low-risk gamble.