Love Jones, Tuesday, September 20, at the Mercury Cafe, is a collection of performers who like their martinis almost as dry as their wit. Along with Chicago's Coctails and Boston's Combustible Edison, the band is part of the burgeoning movement known as "Coctail Nation"; its latest album, Here's to the Losers, documents the members' schmaltzy obsession with retro-lounge aesthetics. In stark contrast to the angry, guitar-driven postpunk stylings predominant in today's underground, these musicians rebel with overtly thick harmonies, bongos and a cheesy irreverence that's infuriatingly infectious (their propensity to cover songs by mid-Eighties pop icons such as Prince is a bonus). Love Jones may be a joke, but it's a pretty good one. Bring your best Vegas smoking jacket and come prepared to dance.