When it comes to avant-garde rock bands, there are usually two distinct routes: noisy cathartic (Sonic Youth, Dead C) and dissonant/drone-y ominous (Spiritualized, This Heat). Then there are the bands that go to a third extreme, exuding a smug "Gosh, aren't we just so zany and quirky?" attitude. Few bands seem to be willing to push the envelope with a sense of humor and a memorable melody. That's why the latest platter by Grampall Jookabox, Ropechain, is so gratifying — it sounds bracingly original yet oddly approachable. The medium of Indianapolis dwellers David "Moose" Adamson and Aimee Brown, Grampall Jookabox don't lend themselves to glib descriptive phrases. A crickets-at-night beat and played-backward mantra-like female choir sounding like Madagascar or Bollywood pop drives "Black Girls." "Let's Go Mad Together" is a send-up of Us vs. Them paranoia and synth-pop (with a killer old-style Black Sabbath riff), while "Strike Me Down" is hip-hop with T. Rex-style vocals for a spaghetti Western, complete with whistling and lonely twang. GJ possess a spirited sense of psychedelic wonder and possibility (with a smidgen of dub, too).