If there's a drop of Celt blood in you, your life will be incomplete should you miss seeing Shane MacGowan and his post-Pogues group, the Popes. Names are irrelevant. You are seeing the Pogues, as but for the late Kirsty MacColl's appearance on 1988's classic "Fairytale of New York," and co-vocalist Cait O'Riordan, who took an early departure from the band. After O'Riordan left, MacGowan was everything essential about the Pogues: The band's brief attempt to continue without him was like a chicken running with its head cut off. MacGowan's vocals are the cries and mumbles of an angel on its last legs, and a dozen or so of the original songs he wrote for the Pogues are as sad, gorgeous, and thrashingly fierce as the timeless traditionals he makes his own.

The Pogues' first (and best) two records, Red Roses for Me and Rum, Sodomy & the Lash (Stiff), are Irish folk played the way it should be, like punk rock: They could slide right between your great-aunt Mary's Clancy Brothers LPs without making the old broad bat an eye. If I Should Fall from Grace with God (1988) was their major-label breakout, and despite producer Steve Lillywhite's heavy-handed studio glossing, it contains some of the band's finest moments. Two passable but undistinguished records, the Pogues' last with their brilliant but unstable leader, came at the end of that decade. In 1995 MacGowan was back with a new band, winkingly called the Popes. The Popes made a respectable album (The Snake) and a completely wretched one (The Crock of Gold, cut in 1997 and so poorly distributed and advertised that it only turned up here last year). If either the 43-year-old MacGowan or his crazed fans cared, The Crock of Gold could have been a career wrecker, but the old stuff is too great a body of work to be damaged by anything he might yet do.

MacGowan affects a crowd like few people I have ever seen. Two-hundred-pound men are tossed in the air like leprechauns; the pit clears momentarily for a sweaty couple's cheek-to-cheek, like a waltz on speed, then closes like the Red Sea; men and women hurl one another around, try out low kicks, Cossack-style, and crash across the floor a dozen at a time to land in a pile of blushing bodies. The music lifts everyone to a higher, nimble consciousness so that a foot never comes down where it shouldn't, the chaos of the crowd functioning precisely, a cosmic tumult steered in every motion by a mad deity. Alcohol is a factor here: Hardcore drunks stagger onto the scene, drink a year's ration of whiskey, and, rubber-limbed, leap into the fray. It would be very scary if everyone weren't so happy, because, whatever you think about Springsteen, Neil Young, Sleater-Kinney, or Marilyn Manson--people LOVE the Pogues, and they are SHITFACED.

MacGowan's last two scheduled appearances here have been canceled, his drunken unreliability having deep-sixed one great band so far. (The only intelligible words spoken by him at the Popes' 1995 set at Under the Rail were, "Glub garrub Seattle--bleagh blub fucking PEARL JAM.") Bad omens, but everyone expected this guy to die 10 years ago. He is an unapologetic mystical drunk, the kind that has a way of living what seems like forever.

The Murder City Devils, a band that kicks ass without removing its heart from its sleeve, are the ideal openers for MacGowan. Hearing the Devils' devastatingly dark Christmas single a couple years back during the holidays, a passenger in my cab sighed, "THAT'S what Christmas is like." The boozy sadness in their songs is not the fetishized theater of 16 Horsepower (or on the finer end of the fake-drunk spectrum, Tom Waits). These guys are the real thing.

Having stared out the round windows of the Cha Cha until to stay meant losing everything else, I urge you to honor the sacrifice of these bands. Drunk, stoned, unintelligible, Shane MacGowan is a real shaman and forges a deep fusion of punk ethos and the folk tradition with a sublimity I cannot imagine will ever be surpassed. I encourage you to arrange some safe transportation home, and get HEROICALLY trashed.