GLEE TIMES TWO: On tonight’s Glee episode, "Duets" (8-9 p.m. on Fox), the choir kids work on their pairings, as Finn and Rachel plan to throw the competition so that Sam can have a shot at winning. Meanwhile, a love triangle between Mike, Tina and Artie develops. The song list includes Elton and Kiki Dee’s “Don’t Go Breaking My Heart,” Jason Mraz and Colbie Caillat’s “Lucky,” Barbra Streisand and Judy Garland’s “Happy Days Are Here/Get Happy,” Ike & Tina Turner’s “River Deep, Mountain High,” as well as a pair of show tunes in “Sing!” (A Chorus Line) and “Le Jazz Hot” (Victor/Victoria). Music for the shows will be available on iTunes tonight. (10/12a)