Broadway: The American Musical, 9-11 p.m., Channels 48, 16; continues Wednesday and Thursday.

In its early days, Broadway wasn't a big-ticket, highbrow place. It offered a frothy brew of entertainment, often from people who had grown up poor, in New York's immigrant families.

Many were Jewish, including Irving Berlin, Fanny Brice, the Gershwin brothers, the Marx Brothers and more. There were Irishmen (George M. Cohan), blacks (Bert Williams, Eubie Blake) and more, forming a musical melting pot.

The first night of this terrific documentary captures those vibrant days. It begins in 1893 when Florenz Ziegfeld Jr. brought his sense of dazzle and showmanship. It concludes in 1933, with fierce blows from movies and the Depression.

It also pauses for the first of many fascinating detours: Ziegfeld - known for flash and fun - produced the 1927 Show Boat, with its masterful music and its deep social conscience.

Worth watching

The Biggest Loser debut, 8-9:30 p.m., Channels 5, 2. Viewers meet a dozen people who want to lose substantial weight. They're split into two teams, then given challenges and temptations. We haven't seen this yet, so we'll stifle our grumbling. If we did grumble, we'd say that win-a-contest weight loss is dangerous, temptations are cruel and this hardly seems worthy of a slot where NBC canceled Whoopi and rushed Last Comic Standing out the door.

Gilmore Girls, 8 p.m., Channels 64, 26. Lorelai double-dates with her daughter Rory. They bring Luke and Dean, respectively.

Alvin and the Chipmunks Meet the Wolfman,

8-9:30 p.m., Disney Channel. We're pretty sure this isn't a Disney classic. Alvin says one of his neighbors is a werewolf.

The George Lopez Show, 8:30 p.m., Channels

9, 22. When Angie loses her job, she makes the tough decision to home-school her daughter.

According to Jim, 9 p.m., Channels 9, 22. Jim wants to prove that men and women don't hear things the same way.

Airplane! (1980), 9-11 p.m., Spike. One of the great comedy movies is back as a wary former war pilot is forced to fly a plane. The humor is so quick and nonsensical that it's easy to keep rewatching.

Scrubs, 9:30 p.m., Channels 5, 2. J.D. walks into the on-call room and finds his former lover Elliot (Sarah Chalke) sleeping with his brother (Tom Cavanagh).

Law & Order: Special Victims Unit, 10 p.m., Channels 5, 2. A baby has been abandoned, with a note saying the mother was kidnapped. Meanwhile, cops suspect that someone is copying a serial killer.

He's a Lady debut, 10 p.m., TBS. Eleven macho guys thought they would be in a tough adventure show. Instead, they're competing to see which can do the best job of impersonating a woman. Some take it seriously and look kind of hot; others don't have a chance.