There are reasons, not necessarily good ones, why Ravel’s ballet — or “choreographic symphony,” as the composer would prefer — isn’t performed all that often (and not within the last generation, if we can believe ISO promo materials). a) It’s Ravel’s longest work at over an hour. b) He extracted two orchestral suites from the work, which are a lot easier to program. c) It calls for both dancers and chorus, meaning that a bunch of different groups have to find the right time to collaborate. This June is the right time for the Indianapolis Symphony Orchestra, Dance Kaleidoscope and the Indianapolis Symphonic Choir, with DK artistic head David Hochoy choreographing and Krzysztof Urbanski conducting. Something of a can’t-miss event if you’re not a neanderthal.