Oct. 25, 2013 -- Katy Perry celebrated her 29th birthday by giving a private concert at the Colorado high school whose spirited lip dub video to her pop anthem "Roar" became a viral frenzy and won "'Good Morning America's 'Roar' With Katy Perry Contest."
Perry chose the winning video, which was shot in a single take and featured over 2,000 students and staff at Lakewood High School in Lakewood, Colo., lip-syncing to Perry's lyrics group by group, from student athletes to cheerleaders to members of the pep band and more, for its school spirit.
"It was thousands of kids coming together to 'Roar' and that's what this competition means to me," Perry told "GMA."
That tremendous sense of school spirit was on display today as Perry arrived in the ultimate pep rally fashion at the school, walking through a sea of thousands of students in orange and black, and took to the stage in a cheerleading uniform to perform, live on "Good Morning America."
The students, whose school mascot is fittingly a tiger, transformed their gym into a concert venue, complete with banners and signs reading "One World, One Roar," for the singer arrival.
Perry, who just released her new album, "Prism," turned 29 today, but said she often feels like a teen at heart.
"I'm 29. I feel great," Perry said to a packed audience of thousands. "I still feel like I'm 13 sometimes. Obviously you can tell by my music and my spirit. I'm so excited about this record and I just love all the participation and the unification …of all of you guys coming together and roaring."
Perry got the crowd roaring with a spirited performance of her hit, "Roar," which featured a jump-rope routine. She also sang her new single, "Walking on Air," and her classic, "Firework."
Courtney Coddington, Lakewood High School's student body president who directed and produced the winning video, and fellow senior Gavin Rudy, an aspiring filmmaker, edited it. Coddington said it was "awesome" how the entire student body collaborated on the winning video.
The school presented Perry with a special Varsity letter jacket and a birthday cake for the occasion.
Lakewood High School's "Roar" video was one of hundreds submitted after Perry put a call out on "Good Morning America" for high schools to submit their own rendition of her mega-hit "Roar," igniting an online frenzy that made local headlines around the country.
Perry scoured through submissions and was inspired by the stories and the creativity. The singer narrowed it down to Lakewood High School and four other finalists -- Pickerington High School Central in Ohio, Cooper High School in Abilene, Texas, Spanish Springs High School in Sparks, Nev., and Verrado High School in Buckeye, Ariz. -- and said picking a winner was "one of the hardest decisions" she's ever had to make.
"So many different high schools came together and I was truly touched. Emotionally, I laughed, I cried. I was blown away by some of the creativity. There were so many different variations and I appreciated all of them. There were a lot of finalists and I really loved that everybody just had that school spirit still," Perry said today on "GMA." "We live in a time where I think where we are really distracted. ... We can be someone else, on our phones ...Everyone came together and just made fantastic videos. School spirit still lives."
Perry tweeted about the event all morning and posted a selfie after the show with the crowd.