The excitement of live television is not without peril. On last Tuesday’s “American Idol” (7 p.m., Fox) contestant Adam Lambert was said to have been incredible. He even received a standing ovation from the professionally cranky Simon Cowell. But like millions of Americans, I didn’t see the performance. And I watched the whole show. Or at least I thought I did.

“Idol” viewers who use a TiVo or DVR to time-shift the experience were robbed of Adam’s performance because “Idol” ran about 10 minutes too long. We got just up to Lambert’s baby pictures and his dad’s insinuating remarks about him not liking sports when time ran out.

Given the stakes and the reported quality of Lambert’s performance, you’d think they would have rerun it on Wednesday night, but they did not. Instead, we got to see a “Making of a Ford Video” segment.

It was interesting to see Frankie Avalon on last week’s result show performing “Venus,” his hit from 1959, Cowell’s birth year. It confirmed something I have always felt about “Idol.”

Avalon is among the stars who came to prominence in the late 1950s after many rock pioneers passed from the scene. With Elvis Presley in the Army, Buddy Holly in his grave, Chuck Berry in jail and Jerry Lee Lewis in disgrace, the industry turned to prefab models like Avalon and Fabian to keep the platters selling.

Avalon is the living embodiment of the harmless and manufactured pop idol, not all that different from the kids from “American Idol” — a distracting performance until someone really great or original comes along. While separated by half a century, the star-making machinery is remarkably similar. Even the first “Idol” movie, “From Justin to Kelly” (2003), seemed directly modeled on the forgettable Avalon-Annette Funicello films of old. Then and now, only the most gullible squares considered Avalon or Kelly Clarkson to be the real deal.

• “Independent Lens” (9 p.m., PBS, check local listings) presents “Taking Roots: The Vision of Wangari Maathai,” a profile of a remarkable Kenyan activist who taught millions of her fellow citizens to plant trees and reclaim millions of acres lost to colonial deforestation and corporate exploitation. The film also offers a brief history of Kenya’s colonial experience and post-independence, a period of crony-ridden dictators who feared and oppressed strong women like Maathai.

Tonight’s other highlights

• The sports-magazine series “E-60” (6 p.m., ESPN) presents “Lord of the Ring,” a profile of professional wrestling’s Vince McMahon.

• Turner Classic Movies celebrates its 15th anniversary with the 1939 favorite “Gone With the Wind” (7 p.m., TCM).

• A high-school jock’s murder casts a spotlight on a self-proclaimed witch on “The Mentalist” (8 p.m., CBS).

• Extremists ransack a laboratory and pay a high price on “Fringe” (8 p.m., Fox).

• “Frontline/World” (8 p.m., PBS, check local listings) looks at the Taliban.

• A tycoon’s son vanishes on “Without a Trace” (9 p.m., CBS).

• An abducted teen returns home after four years on “Law & Order: Special Victims Unit” (9 p.m., NBC).

• A picked-on boy needs help on “Cupid” (9 p.m., ABC).

• Tommy faces the prospect of termination on “Rescue Me” (9 p.m., FX).