If Glee isn’t careful, it’ll start being called a reality TV show rather than a musical sitcom; the all-singing all-dancing comedy has enlisted Adam Lambert, who was runner up in the eight season of American Idol. Showrunner and co-creator Ryan Murphy announced the news on Wednesday with a Tweet.

Adam LambertAdam Lambert and his ridiculous head

"I am thrilled to announce that the super talented Adam Lambert is joining the cast of 'Glee' this fall," he announced. He isn’t the first American Idol alumni to join the show: Jessica Sanchez – runner up of flat season’s show – had a role in multiple shows playing a singer in a rival Glee club.

The singer told The Hollywood Reporter in January 2012 that he feels the scripted singing series is "so cute" and "really paints a picture of what it's like to be an arts kid in high school.” He added, at the time: “Glee' is really irresistible -- it's charming." See what happens when you do a bit of ground work (ahem, sucking up)? Part of Glee’s make up is the fact it includes celebs who play themselves. Sarah Jessica Parker and Kate Hudson have both enjoyed recurring roles. Also appearing on the show were Britney Spears – who had a role early on – Olivia Newton John, Josh Groban, Neil Patrick Harris and John Stamos.

Adam LambertHe's officially a Gleek now

Glee returns with its fifth season Thursday, Sept. 19 at 9 p.m. on Fox and will see Heather Morris, Mark Salling, Amber Riley and Harry Shum Jr. return while Melissa Benoist, Jacob Artist, Becca Tobin, Blake Jenner and Alex Newell all join in on the fun as newcomers.