Being a Canadian musician is like being the middle child in a large family. Your brothers ignore you, belittle you, cuff you on the side of the head and leave you with the smallest pork chop - but if you become famous after you leave home, they'll fawn all over you.

 Ask Deborah Cox, who became the top Canadian R&B artist in history only after moving to Los Angeles.

 After collecting a sheaf of rejection letters from Canadian record labels that claimed their "quota" had been reached, R&B impresario Clive Davis signed the former Celine Dion backup singer to his Arista Records label in 1995. (He recently signed Prince, too, which should go a long way toward changing the Arista's image as "the label that Whitney Houston built.")

 Cox's latest album, One Wish, has sold a million copies.

 That sound you hear is Canadian record executives slapping their heads and uttering a collective "d'oh!"

 Cox performs Tuesday on the main stage at Lilith Fair in Commonwealth Stadium.

 "Sometimes, you got to leave home to be appreciated at home," she says without a trace of bitterness. "It's almost like the minute you somehow have some success in America, then everybody receives you, not just Canada but Europe, Japan, everywhere in the world," she laughs. "It's like you're credible."

 Cox, a devout Christian who grew up in Scarborough, Ont., has plenty of relatives - so she's lived that "family" analogy. "Yeah, when we come home for Christmas, everybody in the family wants to see us, and it's like, 'hey, we were living here and no one wanted to take the time to come and hang out with us.' You're there all the time, they kind of take it for granted."

 Again, no bitterness. It's just the way the world works - and it's been working out rather well for this 26-year-old singer lately. There's the Roots endorsement, talk with Disney to star in kids' musicals and shelf of awards (including a Soul Train Award - the first Canadian ever to win one). Besides, Canada isn't exactly Motown when it comes to urban music. As the de facto standard-bearer for the genre in Canada, she's been feeling the pressure.

 "Yeah, it puts a lot of pressure on me, because I kind of have to wear the Canadian flag," Cox says. "I don't want to disappoint anybody. I don't want to disappoint my Canadian fans or any of my fans, really. But the great thing about it is that I've been received so well and people really love the music. They know I'm from Canada, but that doesn't seem to make a difference."

 Cox says she was initially nervous about being asked to join Lilith Fair, with its stigma of being a folk festival for white women - not to mention that this was her first tour with a full band - "but I pretty much just took the bull by the horns and just went out there and gave it my all and realized I had won over the audience after the show. The (Lilith Fair) audience is a lot more open than I used to think in the past. It's a lot more diverse this year."

 Too bad it's all over. Edmonton is the last date in a three-year reign.

 "It's bittersweet thinking about it, because this is my first year being involved and it's been such a great experience I don't ever want it to end. It would be great to do it again next year, but (sigh) Sarah's (McLachlan) got to have her life as well."

 She should talk. Having toiled ceaselessly since moving to L.A., Cox doesn't have much of a life herself. After Lilith, it's on to host the Lady of Soul Awards, then a trip to Europe and Japan and then, maybe, she and her husband Lascelles Stephens can decide where they want to live.

 Los Angeles, she says, "is not a place that's really condusive to promoting family. I like family environments myself. That's where I feel most comfortable. And then there's not a lot of honesty in general. There's a lot of scams out there. Outside of the weather being absolutely beautiful, those are some of the things I don't really like about living in L.A. You always got to be on guard, you always got to watch your back, you don't really know who's honest and who's cool. But I've been there six years and I've met some really cool people - but they're not from L.A. They're always from somewhere else."

 This calls for a cliche: You can never go home again.

 Tickets to Lilith Fair are $43.50 and available at Ticketmaster (451-8000).