Songfacts®:

• This cover by the Glee cast of Katy Perry's hit single was the top selling song in the US in its debut week with sales of 214,000. The song leaped in at #1 on the Digital Songs chart marking the ensemble's first chart-topper and biggest ever sales week up to that point. Previously, the cast's best week came when its first single, "Don't Stop Believin'," debuted at #2 with 177,000 in June 2009.
  The song also debuted at #8 on the Billboard Hot 100, surpassing "Don't Stop Believin'" for the highest first-week sales of any Glee song.
• The lead vocals were provided by Darren Criss, and it was debuted during Glee's November 9, 2010 episode, "Never Been Kissed," in which Criss made his first appearance as Blaine, an openly gay teen from rival glee club the Dalton Academy Warblers. Criss was accompanied on the track by Beelzebubs, a male a cappella group from Tufts University. The Beelzebubs provided the arrangement and back-up vocals for the performance, and actors playing students from the Dalton Academy Warblers lip-synced to their vocals.
• Criss told MTV News the song's success is down to great collaborators and good timing. "There's a couple of things that stack up in my favor, preceding any shenanigans I may or may not be adding to it," he said. "First of all, it's a great song. Between Dr. Luke, Ben Levin, Bonnie McKee, Max Martin, Katy Perry - those are all pretty strong pop writers. A lot of props go to the Beelzebubs from Tufts University, who arranged the killer arrangement. And the song was attached to a new character that a lot of people had a lot of speculation about. I'm just the lucky guy that got to be sprinkled on top."
• Perry gave props to the Glee version when she tweeted, "Oh...My...Gosh... this just brought a sweet tear to my eye! Teenage Dream on GLEE makes my heart go WEEEEE!"
• This was one of 80 songs by the Glee Cast to enter the Hot 100 in 2010, by far the most by any act in a year in the chart's 52-year history. The previous highest haul was the Beatles' 31 entries in 1964.