Jay Leno steps in for Jimmy Fallon: How has late-night changed since Leno left?

Jay Leno contributed to Jimmy Fallon's monologue on a recent episode of NBC's 'Tonight.' The late-night TV landscape looks a lot different than when Leno departed the program.

Viewers tuning in for NBC’s “The Tonight Show with Jimmy Fallon” on Feb. 17 encountered a familiar face. 

Former “Tonight Show” host Jay Leno popped in to present the monologue for the night with Fallon, with Leno delivering jokes about, among others, Hillary Clinton and Donald Trump. 

Fallon took over the show in 2014 after Leno had hosted for more than 20 years. 

The current host jokingly pretended to be injured, saying, “This is ‘The Tonight Show.’ The monologue has to go on,” before Leno entered. 

Leno’s new program “Jay Leno’s Garage,” which focuses on cars, debuted on CNBC this past October.

Fallon began hosting “Tonight” shortly before several other new hosts debuted on late-night shows.

Soon after Fallon arrived, Stephen Colbert of “The Colbert Report” took over for David Letterman on CBS’s “Late Show,” while actor James Corden took over for Craig Ferguson on CBS’s “Late Late Show.” Seth Meyers of “Saturday Night Live” had arrived at NBC’s “Late Night,” formerly hosted by Fallon, right around the same time Fallon debuted on “The Tonight Show.” 

How has “The Tonight Show” and late-night TV in general changed since Leno departed? For one, Fallon has increased viewer interest in the show, particularly young viewers. 

Since debuting two years ago, Fallon has given NBC the two highest-rated seasons for “Tonight” in the last six years for total viewers and for the valued demographic of viewers 18-49. 

“No one has been able to match the consistency and dominance of Jimmy Fallon,” Variety editor Rick Kissell wrote of Fallon’s last two years. 

In addition, past time-slot match-ups like Leno and Letterman were marked by on-air fighting. Relations between the current big names in late-night seem much friendlier. 

“There’s a huge difference ... between shows slugging it out for guests or ratings and the highly personal, high-stakes conflict that until recently defined the late-night time slot,” Vulture writer Josef Adalin wrote. 

In addition, the late-night show emphasis on viral clips has increased, with Fallon and Corden in particular becoming known for such segments as the “Tonight Show” lip-sync battles and other games and the “Late Late Show” “carpool karaoke” segments. 

This helps address the fact that Fallon and his late-night comrades are producing these programs in an Internet-based age where TV habits have changed hugely.

“It is absolutely made for the modern television age, where networks are not only looking to attract viewers but also spur online engagement,” Guardian writer Brian Moylan wrote of Fallon’s lip-sync battle segments.

Elsewhere on the late-night dial, TBS recently addressed the lack of female hosts across all networks, especially since the departure of Chelsea Handler from her late-night show on E!. Former “The Daily Show” correspondent Samantha Bee recently debuted her new show “Full Frontal” on TBS, and reviews so far have been very positive.

“All those fans who worried that ‘The Daily Show’’s go-for-the-jugular political satire left when host Jon Stewart departed last year can rest easy because Samantha Bee is bringing the pain just like Stewart used to,” NPR writer Eric Deggans wrote. “Bee has brought that instinct for sharp satire to her own well-crafted weekly show just in time for the 2016 election season. Welcome back, Samantha. We didn't know how much we needed you.”