Long before YouTube or mobile phones with video capabilities, a little-known rock club in the Lower East Side of New York served as a premier platform for launching some of the biggest bands in rock 'n' roll. As the stomping ground for iconic and enduring punk acts such as the Ramones, the Dead Boys, Talking Heads and Patti Smith, CBGB became famously recognized as the birthplace of the American punk movement.

And now, 40 years later, Hollywood has tasked Savannah with the retelling of the legendary nightclub and its ambitious founder Hilly Kristal in the movie "CBGB", which hits theaters Oct. 11.  

But most of us already knew this - especially after witnessing Savannah's grunge makeover last summer around various parts of the Historic District. Congress Street, in particular, saw the most activity, thanks to the famous CBGB awning stationed near The Paula Deen Store and Sapphire Grill, plus a lineup of heavy hitters including Alan Rickman, Stana Katic, Ashley Greene and Justin Bartha.

Among them was also Rupert Grint, famed "Harry Potter" star, whose striking resemblance to former Dead Boys rocker Cheetah Chrome caught the eye of "CBGB" writer and director Randall Miller. 

For Grint, the experience fulfilled a lifelong dream.

"It was just so fun to pretend to be in a band, which is something I've always wanted to do," he said.

After a decade of starring as Ron Weasley in the magical phenomenon "Harry Potter," joining the cast of "CBGB" was a unique experience for Grint. The rock biopic marks not only one of his first post-"Potter" projects, but also his first American film.

It was "a different kind of world," the actor said. "It was one of the first things I've done since finishing 'Potter' really, and when you leave that bubble, that kind of comfort, it's quite disorienting whenever you go on any set."

On the upside, "CBGB" reunited Grint with his former "Potter" co-star Alan Rickman, who portrayed the sneering Professor Snape in the film franchise. Having a familiar face on set helped during the filming of "CBGB," Grint said of Rickman, who dons a shaggy wig as Kristal in the film.

Shooting in the Hostess City wasn't so bad, either. 

"We all really loved Savannah," Grint said. "I mean, it was interesting, because obviously it was supposed to be New York. So we were quite curious to see how they were going to transform Savannah. But they did a really good job. It was just a great atmosphere, lovely place." 

Also "boiling hot," Grint added.   

As far as Grint's performance goes, Potterheads should prepare for a completely new side of the actor in "CBGB," which further sheds his former image as the loveable, wand brandishing - and fully robed - wizard. In one of the film's exclusive clips, Grint drops his pants and bares his butt for the camera while Genya Ravan (Katic) gets frontal exposure to Grint's "proof" that he's a genuine redhead. 

"We had to do some disgusting things," Grint said. "I mean, the Dead Boys were really hardcore - very spontaneous and just crazy."  

While Grint said he enjoys a lot of punk rock music, he admits, "I wasn't actually familiar with the Dead Boys; that was a new one for me. But I really loved their songs, actually, and I got quite into them."

With the real Cheetah Chrome watching the scenes on set, Grint said he got to know him pretty well. 

"I couldn't believe he was still breathing after reading what kind of stuff he was doing back then," Grint said. 

The pressure to accurately portray the former guitarist's raging lifestyle was the main focus. 

"It was a challenge playing a living person who is on set watching most of the scenes," Grint said. "I wanted to get it right and do him justice."

One thing that came a little easier was rocking out with Bartha, who plays Dead Boys' frontman Stiv Bators in the flick. 

"I had to draw on his bumcheeks, so to do that you get to know someone quite well," Grint said. "We had that kind of unity as a group. When we were on stage, it was just amazing."

Many might be wondering what bizarre role Grint could take on next, but one thing is for sure: His wand is stowed away for good. 

Following last month's announcement that Warner Bros. Studios and Harry Potter author J.K. Rowling are developing another film set in the "Potter" universe, fans held a glimmer of hope the project would reunite the franchise's biggest stars - even though the story will be set 70 years prior to Harry Potter's journey. (It's worth mentioning that director Peter Jackson proved it could be done after bringing back Frodo for a brief appearance in the "Lord of the Rings" prequel, "The Hobbit").

"I don't know how it would work, to be honest," Grint said of the slated film. "I think I kind of closed the door on that now. As much as I loved it and it was a huge part of my life, I think it ended at the right time. But, yeah, I'm happy to just watch that one."