Aww, the High School Musical cast really are all in this together - with the news that they've reunited to celebrate the 10th anniversary of the Disney Channel movie that took over the world.

We can't quite believe it's been a decade since we heard 'Breaking Free' for the first time. But years do indeed pass - and cast members do indeed look different. So join us as we celebrate what the High School Musical cast look like then and now...

1. ZAC EFRON (Troy)

High School Musical then and now: Zac Efronpinterest
Disney Chan / Everett / Frazer Harrison / Getty//ELLEMEN

Zac Efron is only sending in a video message to the reunion; perhaps because he didn't want to revisit this hairstyle. Zac might now be a bona fide sex symbol movie star, but we've always struggled to get on board with that - mainly because all we can remember is this Troy look.

2. VANESSA HUDGENS (Gabriella)

High School Musical then and now: Vanessa Hudgenspinterest
Disney Chan / Everett / Jason LaVeris / FilmMagic//ELLEMEN

Unlike Zac, Vanessa is recognisably the same person - but she's certainly 'broken free' of goodie two-shoes Gabriella, appearing in movies like Sucker PunchSpring Breakers and Machete Kills. And right now, we're excited about the fact that she will play Rizzo in the upcoming Fox musical Grease: Live.

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3. ASHLEY TISDALE (Sharpay)

High School Musical then and now: Ashley Tisdalepinterest
Disney Chan / Everett / Jon Kopaloff / FilmMagic

Ashley was as close to a baddie as you get in a Disney Channel movie, with Sharpay trying to sabotage Troy and Gabriella (how dare she). Since then Ashley has starred in short-lived cheerleading drama Hellcats, released some music and popped up in Scary Movie 5. Oh, and this year she'll voice Cinderella in the animated movie Charming - which also stars Wilmer Valderrama, Demi Lovato, John Cleese, Avril Lavigne, Keyshia Cole and Sia. In other words, it sounds incredible.

4. LUCAS GRABEEL (Ryan)

High School Musical then and now: Lucas Grabeelpinterest
Disney Chan / Everett / Alberto E. Rodriguez / Getty//ELLEMEN

Sharpay's dumb brother Ryan had terrible taste in headgear, so it's pleasing to see that Lucas has ditched the hats and embraced the glasses. He's currently best known for his role in the popular US drama Switched At Birth.

5. CORBIN BLEU (Chad)

High School Musical then and now: Corbin Bleupinterest
Disney Chan / Everett / Tasia Wells / FilmMagic//ELLEMEN

We'll always have a soft spot for Corbin Bleu - mainly due to his part in the undisputed best song of High School Musical, 'Get'Cha Head in the Game'. Since High School Musical he's released a couple of albums, appeared on Broadway and - our favourite - came second in season 17 of Dancing with the Stars (he lost out to Glee's Amber Riley).

6. MONIQUE COLEMAN (Taylor)

high school musical then and now monique colemanpinterest
Disney Chan / Everett / Michael Tran / FilmMagic//ELLEMEN

Ah, Chad and Taylor: truly the Romeo and Juliet of our times. Taylor was sniffy about basketball players, Chad sneered upon 'scholastic decathlon team members', and of course they ended up getting together. Since that romantic rollercoaster, Monique - who appeared on The Suite Life of Zack & Cody - has also taken part in Dancing with the Stars (she came fourth). She's also become a UN Youth Champion and set up an inspirational website for young people called Gimme Mo'.

7. BART JOHNSON (Jack)

high school musical then and now bart johnsonpinterest
Tommaso Boddi / WireImage//Disney

Pfft - Jack, aka Troy's dad, slagged off theatre and was all about the sports (until he realised how totally awesome his son was at singing, obviously). We've just about forgiven him, and if you watched NCIS last year, you might have spotted him playing 'a marine' in one episode.

8. ALYSON REED (Ms Darbus)

high school musical then and now alyson reedpinterest
Disney Chan / Everett / Jesse Grant / WireImage//ELLEMEN

Ugh, just imagine if Ms Darbus had refused to let Troy and Gabriella audition because they were too late. Then what? It would have been a much shorter movie, that's for sure. Anyway, Alyson's kept very busy on TV, appearing in everything from Desperate Housewives to Bones to Grey's Anatomy to Modern Family to Silicon Valley. But does she still hate mobile phones?

The High School Musical special will air in the US on January 20 at 8pm ET on Disney Channel, followed by a cast interview to be broadcast on January 21.