TONIGHT'S MUST-SEE

"American Masters: Atlantic Records: The House That Ahmet Built," 9 p.m., PBS. Ahmet Ertegun fit no image of an American music giant. He was the son of Turkey's ambassador to the U.S. He was a scholarly looking kid. But he loved American jazz and rhythm-and-blues and more. He created Atlantic Records and impacted American music history. This is a rich biography, spiced with performance clips and comments.

OF NOTE

"Bones," 7 p.m., Fox. An astronaut has been killed in a fall, apparently from great heights.

"Thank God You're Here," 7 p.m., NBC. Fred Willard, a veteran of such improvisational comedy, is one of the guests. Others are Fran Drescher and Tom Arnold, plus Angela Kinsey of "The Office."

"Secrets of the Dead: Herculaneum Uncovered," 8 p.m., PBS. Most people have heard of Pompeii, but what about its neighbor? The smaller Herculaneum was buried quickly when Mount Vesuvius erupted in 79 A.D.; now it's an archaeological treasure, an entire city preserved for 2,000 years. This fascinating documentary looks at it — and at the threat to modern Naples.

"According to Jim," 7 p.m., ABC. The annoying Cindy Devlin is divorcing. Now Jim is scrambling to keep Andy from marrying her.

"Notes From the Underbelly," 7:30 p.m., ABC. Julie's having her baby now and Eric is trying to get there in time.

"Lost," 8 and 9 p.m., ABC. If you missed last week's episode, catch the rerun and skip the rest of this paragraph. For everyone else, let's review: We learned that Juliet is still scheming with The Others, sending back a report on the pregnant Sun. We also learned that the outside world has heard everyone died on this crashed flight. Does this mean, as some viewers feel, that the island is Purgatory? Or that there's a cover-up? We'll learn a little more tonight; meanwhile, Locke makes a vigilante move.

"American Idol," 8 p.m., Fox. The show adjusts to its cruel hoax last week, when it implied that Jordin was out, then said no one was leaving. Now two people are ousted tonight; also, Bon Jovi performs.

"CSI: NY," 9 p.m., CBS. It's crossover night, when Danny Pino guests as Detective Scotty Valens, his "Cold Case" character. His lab evidence makes Stella (Melina Kanakaredes) a murder suspect.

"Medium," 9 p.m., NBC. Two stars from past Fox hits appear. Jason Priestley of "Beverly Hills, 90210" is the murder suspect; Neve Campbell of "Party of Five" begins a three-episode stay as Allison's friend Debra.