If you aren't up for surprises, stop reading now: The music of Battlehooch offers no shortage of startling turns and unexpected landings. The six-piece San Francisco outfit bills itself as "shape-shifting orchestral rock," but that's only half the story. Battlehooch sounds like what would happen if a group of musical prodigies got trapped in an instrument storage locker with a dozen boxes of Cap'n Crunch and a gallon of mushroom tea. We could point out the elements of funk, comment on the presence of exotic flutes, note the howling lines of brass, mention the searing guitar leads, or bring up the frequent changes in tempo. But the only way to really get it is to see it live. This is a great time to do it: All through October, Battlehooch is holding a Wednesday night residency at the Knockout. With different openers every night — and these maniacs in the headlining slot — you'll never know quite what to expect. That's a good thing.