The first big "show" investment on the Strip in more than a year really needs those quote marks. Discoshow, a spirited salute to 1970s excess, blurs the line between a show as we used to know it and the “immersive environmental theater” the film-it-with-phone crowd is said to crave. Producer Spiegelworld is really swinging for the fences to bring something new to the Strip after its smash hit Absinthe (and a more modest one, Atomic Saloon Show). But at least in the early going, the venue outshone the content. The producers have carved a huge and truly impressive complex out of an abandoned sports book and other dark corners of the former Imperial Palace: a lounge, a restaurant called Diner Ross (after Spiegelworld impresario Ross Mollison), another bar area for the pre-show gathering; and the square, standing-room-only venue itself, where performers surround you on raised catwalks in front of video walls. All of it is themed to 1970s-era New York with a carved-out warehouse vibe, from the neon, mirror-ball tile and framed record albums to the graffiti. Too bad the show itself doesn't live up to its surroundings. At little more than an hour long, it's all dancing, with no live singing or variety acts, not much speaking, and even less story-telling—a sketch of one about a wallflower transforming into a disco doll. But the dance-along spirit is contagious, and the girls' night-out crowd seems to love the chance to dust off their boogie shoes.