Glee is a musical comedy-drama television series that airs on Fox in the United States. It focuses on the high school glee club New Directions competing on the show choir competition circuit, while its members deal with relationships, sexuality and social issues. The initial main cast encompassed club director and Spanish teacher Will Schuester (Matthew Morrison), cheerleading coach Sue Sylvester (Jane Lynch), guidance counselor Emma Pillsbury (Jayma Mays), Will's wife Terri (Jessalyn Gilsig), and eight club members played by Dianna Agron, Chris Colfer, Kevin McHale, Lea Michele, Cory Monteith, Amber Riley, Mark Salling and Jenna Ushkowitz. For the second season, formerly recurring cast members Mike O'Malley, Heather Morris and Naya Rivera were promoted to the main cast. The series was created by Ryan Murphy, Brad Falchuk and Ian Brennan, who first conceived Glee as a film. The three write all of the show's episodes and Murphy and Falchuk serve as the show's main directors. The pilot episode was broadcast on May 19, 2009, and the first season aired from September 9, 2009 to June 8, 2010. The second season began airing on September 21, 2010, and a third season has been commissioned. Glee features on-screen performance-based musical numbers that are selected by Murphy, who aims to maintain a balance between show tunes and chart hits. Songs covered in the show are released through the iTunes Store during the week of broadcast, and a series of Glee albums have been released by Columbia Records.