Actor/musician Darren Criss joined the cast of Glee in November 2010. Originally hired as a guest star, he became a series regular several weeks after his first episode, when the Glee version of Katy Perry’s “Teenage Dream” — featuring Criss on lead vocals, with backup harmonies from collegiate a cappella group the Beelzebubs — because the show’s first single to top the digital charts. Born in 1987, Criss spent his childhood working as a professional stage actor in San Francisco and playing music with his brother, Chuck Criss, who later joined Freelance Whales. Darren enrolled at the University of Michigan in 2004, where he studied acting and helped found a student-run theater troupe named Team StarKid. A Very Potter Musical, a musical comedy that spoofed the Harry Potter franchise and starred Criss in the titular role, became Team StarKid’s most popular show, racking up more than 25 million views on YouTube and catapulting Criss (who’d also written most of the music) into the spotlight. After graduating in 2009, he starred in five episodes of ABC’s Eastwick, made a guest appearance on Cold Case, and released a self-produced EP, Human, which hit iTunes several months before his Glee debut.