'High School Musical' graduates to the big time' The TV phenomenon arrives Xi ' -"In concert BY MICHAEL GlLTZ The Disney 1V movie "High School Musical" was the biggest pop cultural phenomenon of 2006 -and it's set to be the biggest one of 2007 as well.</p><p> The "Grease"-like songfest was an unprecedented hit on cable, airing repeatedly and draw ing massive viewership every single time.</p><p> The soundtrack is the best-selling album of the year.</p><p> Most of the cast members are on tour with the show, hitting Nassau Coliseum on Dec. 29 and New: Year's Eve.</p><p> And in February they start filming the sequel.</p><p> For star Corbin Bleu - a veteran actor and dancer even though he's only 17 years old -the fun has only begun, "I'm actually on the tour bus riding to the next stop," says Bleu, who plays basketball star Chad Danforth and best buddy to the hero, Zac Efron. (In the film, Efron wants to play basketball but also is drawn to the smart new girl and the possibility of auditioning in the school's new musicaL) "There are like six buses," says Bleu, the son of parents who are also in the entertainment business . "I'm in my little bunk right now.</p><p> Oh, my gosh," he says, sounding exactly like someone who'd be in a high school musical, "we're hav ing so much fun." Bleu is performing to some 15,000 fans a night and trying to map out his schedule for the next year, "While I'm on tour, my new movie 'Jump In" premieres Jan 12 on the DIS ney Channel," he says, In it, Bleu stars as a teen boxer who gets drawn into the world of competitive jump roping (you read that right).</p><p> His dad -played by Bleu's real·life dad, actor David ReiverS,' -is not amused. 1 "Then I got back to Hawaii to film " the two-hour finale to my Discovery Channel show, 'Flight 29 Down' [a se ries about people stranded after a plane crashl.</p><p> Then I go to Utah to film 'High School Musical 2: And while I'm out there, my first solo album will come out in April.</p><p> There's so much going on right now." In the past year, Bleu has made his first trip to Europe (where "HSM" was also a big success), gone to the Emmys (where Rosie O'Donnell thrilled him by saying how much she loved (he movie) and finally heard himself on the radio when the single "Push It to the Limit" (which is on his first solo album) got some airplay, Didn't that happen with "High School Musical"? "No'" Bleu laughs. "I don't have any solos in 'High School MusICal' The only time you actuall~\.' hear m.Y voin·' is on 'Stick to the Status Quo,' when' ,OU can hear ll1e say the WOl U 'Wh,II')' But al least 1 got a dance solo' •