pennstation5There’s a terrific, succinct report on “American Experience” (PBS, 9 p.m., check local listings) about “The Life and Death of Penn Station.” The monumental train station, privately built to evoke the grandeur of Rome, brought nobility to every commuter (though its building meant clearing blocks and blocks of tenaments in the Tenderloin).

The engineering achievement of building a tunnel under the Hudson (and more difficultly, the East River) is told in in a clear way and may be Penn Station’s lasting achievement (the Pennsylvania railroad used to have to stop at Jersey City with anybody going further having to take a ferry).

The only thing not farsighted about the industrial captains who oversaw the huge project was the longevity of train travel. Opened in 1914, the railroad had to destroy the station in 1963 and sell its real estate rights to Madison Square Garden and skyscrapers to keep from going bankrupt.

It ended one of the great public buildings on Earth in a shocking demolition that laid the groundwork for all future landmark preservation, particularly for Grand Central, whose interlocking story with Penn Station is the only part of the story left untold in the hour.

I’m a huge fan of just about everything on “Frontline” (PBS, 10 p.m.), except for the youth baiting reports by Douglas Rushkoff. His last expose on kid style setters, “The Merchants of Cool” in 2001, while interesting, played on assumptions on kids and jargon.

His new, sort-of follow-up, “Generation Like” is much better, focusing on YouTube stars so keen to brand themselves online that they literally don’t know the meaning of selling out. You’ll like the report but not in a “Facebook like” kind of way.

Voting has already begun on “American Idol” (Fox, 8 p.m.). When judges abdicated their duty and couldn’t decide on their 30th semi-finalist, it was up to viewers.But the rest of the 15 girls were decided upon and will sing tonight; the boys tomorrow. On Wednesday, the Top 13 or however they determine it will be named. Three nights of “Idol” may be overkill, but at least there’s no “X Factor” coming back, and the new season of “The Voice” doesn’t resume until next week.

One key link to “Idol” past appears today with Randy Jackson, slimmed down and with a slimmed down role — as head mentor, presiding over two popular runners up, Adam Lambert and Chris Daughtry. They will dispense advice to contestants and presumably disappear. But what can singers now be told? They’ve been watching this show since they were kids, back when Randy was a bigger dog.

“The Tonight Show starring Jimmy Fallon” (NBC, midnight) keeps up the A-list onslaught with Jerry Seinfeld, Kristen Wiig and Lady Gaga, who popped in for a second on the premiere Monday, which did pretty good in the ratings last night — not quite as strong as Jay’s goodbye but equal to the first “Tonight” show by “Conan” (TBS, 11 p.m.), who tonight brings in Mel Brooks to talk about the legacy of Sid Caesar, who died last week.

As for the Winter Olympics (NBC, 8 p.m.) you could at least say ice dancing is over. tonight has giant slalom in women’s Alpine skiing, men’s freestyle halfpipe skiing, women’s short track relay and women’s bobsled. Having Bob Costas back makes a big difference, it turns out.

Smuggling coffee out of Thailand gets Todd stopped at the Myanmar border on “Dangerous Grounds” (Travel, 9 p.m.).

Seasons are turning: “100 Days of Summer” (Bravo, 10 p.m.) reaches its finale at a cabin in Wisconsin.

“Tosh.0” (Comedy Central, 10 p.m.) is back with new episodes, constituting its sixth season start.

You probably don’t remember who the best editing nominees from 1959 were. They included “Ben-Hur” (TCM, 8 p.m.), “North by Northwest” (TCM, midnight), “Anatomy of a Murder” (TCM, 2:30 a.m.) and “The Nun’s Story” (TCM, 5:30 a.m.).

Men’s college hoops tonight includes Texas at Iowa State (ESPN2, 7 p.m.) Kentucky at Mississippi (ESPN, 7 p.m.), George Washington at Richmond (NBC Sports Network, 7 p.m.), South Florida at Louisville (CBS Sports network, 7 p.m.), Villanova at Providence (Fox Sports 1, 7 p.m.), North Carolina State at Clemson (ESPNU, 7 p.m.), Iowa at Indiana (ESPN, 9 p.m.), Butler at St. John’s (Fox Sports 1, 9 p.m.), Georgia at Tennessee (ESPNU, 9 p.m.) and Utah State at San Diego State (ESPNU, 11 p.m.).

Think of the psychological benefit of watching spring college baseball: Northern Colorado at TCU (Fox College Sports, 7:30 p.m.).

Daytime Talk

Kelly & Michael: Matt LeBlanc, Kit Harington, John Legend. The View: Wayne Brady, Paul Fronczak, Jerry O’Connell. The Talk: Craig Ferguson, Michael Yo. Ellen DeGeneres: Harry Connick Jr., Gabrielle Union. Wendy Williams: Dule Hill.

Late Talk

David Letterman: Sage Kotsenburg, Cole Swindell. Jimmy Fallon: Jerry Seinfeld, Kristen Wiig, Lady Gaga. Jimmy Kimmel: Bill O’Reilly, Kit Harington, Phantogram. Craig Ferguson: Ted Danson, Kristen Schaal. Tavis Smiley: Will Forte, Earl Klugh. Jon Stewart: Kevin Spacey. Stephen Colbert: Brian Greene. Arsenio Hall: Jackie Christie, Brittish Williams, Sunday Carter, Corey Holcomb. Conan O’Brien: Mel Brooks, Langhorn Slim.