Fallon debuts on 'Tonight Show'February 18, 2014
Jimmy Fallon walks the red carpet before attending the 64th Annual Primetime Emmy Awards in Los Angeles, California on September 23, 2012.
(CNN) -- To thunderous applause and a Cheshire cat grin, Jimmy Fallon walked on to the stage at the NBC Studio in New York Monday night -- the new host in the old home of the "Tonight Show."
"I am Jimmy Fallon and I will be your host -- for now," he said.
His first joke out of the way, he spent the next few minutes introducing himself to the audience -- his childhood, his family, his career. He was pretty subdued through it all.
But then when the formalities were out of the way, he re-entered the show through the blue curtains -- the ever-hip Roots playing him in -- and started his show proper: the usual monologue and his usual self.
The laughs came easy.
The real challenge will be tomorrow, and the next day, and the next month.
For most of his 22 years, Fallon's predecessor, Jay Leno, sat at the top of the late night talk show totem pole.
Sure, Leno was critically panned for his milquetoast interviews and his predictable jokes. But the masses loved him.
How will Fallon fare?
That's the big question.
For one thing, the late night landscape has changed. The hosts -- like Conan O' Brien and Jimmy Kimmel -- skew younger. And with Fallon, NBC hopes the audience will too.
While one-time host Johnny Carson has been the template all future hosts emulated, Fallon says he will fashion his stint after a different host: The original host, Steve Allen.
Allen's was a free-wheeling hodgepodge of chat, skits, piano-playing, ad-libbing, man-on-the-street interviews and loopy stunts.
Fallon is a capable guitarist and musical mimic who has done dead-on parodies of Bruce Springsteen and Neil Young, among others. Bits with guests such as Michelle Obama and Justin Timberlake have gotten millions of views online, and segments such as "Slow Jam the News" have some of the whimsical quality that Allen was fond of.