There's a propensity among fans of the Grateful Dead to trade in bootlegs of the jam band's finest live performances, speaking about certain dates and venues as if they were canon. One such performance is the Dead's stop at Cornell University in May of 1977, often lauded as one of their greatest. If you've never heard it, it's widely available on the Internet and worth a download. If you have heard it, and are looking to get just another step closer to the now-impossible reality of the Dead live, then you might want to check out Dark Star Orchestra, playing tonight at 8 p.m. at Club Cinema. Dark Star, or DSO as they're often called, have separated themselves from the glut of Dead tributes by not simply covering popular songs, but recreating entire live performances with methodical precision. Their sets are so eerily similar to the source material, that even the Grateful Dead themselves -- the surviving members anyhow -- have trouble discerning them from the real thing. Said the Dead's Bob Weir after he appeared alongside DSO: "A couple of times when I had my back to John [Kadlecik, DSO's lead vocalist] onstage and he started to sing, I had this weird sense that it was Jerry."