AceShowbiz -

Hot on the heels of his deal to become a regular on popular TV series "Glee", Darren Criss hit studio for a top-secret recording session last week. The Blaine depicter was snapped setting up his microphone at a Los Angeles studio on Tuesday, November 23.

The 23-year-old actor looked casual in the picture, wearing gray V-neck T-shirt. Details on the project that he is currently working are still kept under wraps. It might be for his appearance on "Glee" or for his music project. In fact, he has played a secret show for fans at The Mint on November 13.

Darren Criss charmed TV viewers and music listeners with his rendition of Katy Perry's "Teenage Dream" which led him to sign a deal as "Glee" regular star. Featured on episode "Never Been Kissed", the remix sold 55,000 copies on its first day on iTunes.

It debuted at No. 1 on the digital sale chart, surpassing the previous first-day sales record of the "Empire State of Mind" rendition. By the end of the first week, it pulled in around 214,000 copies, landed at No. 8 on Billboard Hot 100, and became highest first-week sales of any "Glee" song.

Next, Criss will be covering Train's "Hey, Soul Sister" in an episode called "Special Education". It will air on November 30 and follow New Directions heading to the big Sectionals competition against the Warblers and the Hipsters.