Unpretty

Ladies and gentlemen, we are floating in cyberspace. As TLC kick off their first tour in nearly five years to a less-than-capacity crowd in Toronto's Air Canada Centre on Oct. 22, a crescendo of computerized bleeps and blats envelops the arena. A mammoth robotic vixen — Virtual Vice (pronounced ''Vicky'') by name — appears on the huge screen at the rear of the stage. It's disorienting and dramatic, a Matrix moment. You half-expect to hear Laurence Fishburne welcoming you to the real world, but soon Vice is introducing the flesh-and-blood stars of the evening: Lisa ''Left Eye'' Lopes, 28 (''Personality: crazy,'' Vice intones), Rozonda ''Chilli'' Thomas, 29 (''Personality: sexy''), and Tionne ''T-Boz'' Watkins, 29 (''Personality: cool''), the Atlanta-based trio whose multiplatinum third album, FanMail, has spawned two of 1999's most inescapable anthems, ''No Scrubs'' and ''Unpretty.''

As the group launch into set opener ''Silly Ho,'' they dance with jerky, machinelike precision, their shimmering silver outfits making them look like androids. You find yourself fearing they'll take this Devo-like shtick too far. Not to worry...

''What's up with the lights?'' demands Lopes testily between songs, calling the attention of 5,500 fans to some unseen glitch. ''This ain't how we programmed the lights for the show.''

Ah, Left Eye. The most controversial member of the group — it was she who, in 1994, was arrested for burning down the house of her then beau, former Atlanta Falcons wide receiver Andre Rison — can be counted on to inject some chaos into the mix. Where the baby-faced Chilli projects a palpable sweetness and T-Boz is a combination earth mother and homegirl, Left Eye radiates danger and unpredictability. Prior to her solo spot in the show, during which she performs a magic act, she rattles off definitions of the word crazy: ''Unsound of mind, mentally unbalanced, deranged...'' She savors each phrase like a choice morsel.

As it turns out, her magic tricks won't cost David Copperfield any sleep. But one of them provides an analogy with what's really going on with TLC these days.

''Here we have a string that's been treated with nitroglycerin,'' says Left Eye, grinning loopily. ''And here we have a lighter....''

One week earlier, Chilli and T-Boz are sitting high above the crisp autumnal splendor of Central Park in a plush suite in New York's Trump International Hotel & Tower. Conspicuous in her absence is Left Eye, who's flown home to Atlanta after a fitful few days of press and radio appearances. It's noted that 48 hours before, Lopes had arrived late to and left early from an EW photo shoot, seeming to hold herself apart from the group. She was also a no-show for TLC's appearance on MTV's Total Request Live earlier in the week. Such apparent lack of unity feels particularly significant now, with the group embarking on their first-ever headlining tour, and just months after a Vibe cover story in which Left Eye proclaimed she'd ''graduated from this era'' and could not ''stand 100 percent behind this TLC project.'' With Left Eye working on her first solo album, inquiring minds want to know: Is the biggest-selling female trio in history in danger of being reduced to a duo?