For the second year running, “American Idol” (7 p.m., Fox) airs an “Idol Gives Back” night, a show focused on charity and studded with guest appearances by celebrated singers and stars, including Robin Williams, Celine Dion, Forest Whitaker, Billy Crystal, Dane Cook, Kiefer Sutherland, Jennifer Connolly and Amy Adams.

¢ Thurston Moore of Sonic Youth narrates “Inside Straight Edge” (9 p.m., National Geographic), a documentary about a musical subculture a million miles removed from the happy confines of “American Idol.”

Inspired by the punk rock of an earlier generation, Straight Edge kids participate in a hard-core music scene that extols a proud lifestyle that rejects drugs, alcohol and tobacco. While many Straight Edge kids embrace the movement as a way to stay clean and positive, a militant faction has taken to vigilante attacks on drug dealers or beating up strangers who just happen to be drinking or smoking in the wrong place at the wrong time.

“Inside” takes a balanced approach, talking to kids and parents who see the positive side of the movement, as well as militants past and present who employ a rhetoric of paranoia, vigilance and a need for social “cleansing” that is truly chilling.

¢ The “American Masters” (8 p.m., PBS, check local listings) presentation “Jump at the Sun” profiles author Zora Neale Hurston, a popular black author in the 1930s and 1940s who died in relative obscurity in 1960 only to be rediscovered and celebrated in recent decades. Her works, including “Their Eyes Were Watching God,” have become required reading in many literature classes. The film includes a dramatic re-creation of a 1943 radio interview with the author, as well as archival footage and interviews with surviving friends and colleagues as well as writers Alice Walker and Henry Louis Gates Jr.

It’s not clear how the woman profiled here would react to her recent entry into the academic pantheon or her embrace by the politically correct. She was clearly an iconoclast from an early age, challenging the expectations of behavior for a black woman born in Florida in 1891. She was also deeply conservative and an outspoken Republican.

Her whole career seems in proud opposition to the assumption that black authors must describe life only through the prism of discrimination, brutality and victimhood. As a novelist, folklorist and anthropologist, she described black life in the South as she saw it and not how it fit into any crusader’s idea of reform.

In a famous quote, she proudly rejects racial discrimination, not because it is crushing but because it is absurd. “It merely astonishes me. How can any deny themselves the pleasure of my company?”

¢ Scheduled on “Primetime” (9 p.m., ABC): Randy Pausch, a 47-year-old professor and father of three suffering from pancreatic cancer, has written a book called “The Last Lecture” (Hyperion 2008) and talks to Diane Sawyer.

Tonight’s other highlights

¢ A mother of four laughs at the chaos around her on “Supernanny” (8 p.m., ABC).

¢ Adam and Jamie turn an airport runway into their project on “Mythbusters” (8 p.m., Discovery).

¢ A suspicious fire guts Stella’s apartment on “CSI: NY” (9 p.m., CBS).