NEW YORK - Ask Neil Patrick Harris how he sees his job as host of the 2009 Tony Awards, and the star of TV's

How I Met Your Mother

says judiciously: "Ringmaster at the circus - I want to be strong enough to earn your trust but be able to allow all the specialty acts to shine."

And this year's ceremony, to be televised live Sunday by CBS (8-11 p.m. EDT) from Radio City Music Hall, is packed with enough entertainment to keep its host very busy indeed.

Star performances will be abundant - from Elton John and the cast of Billy Elliot to Dolly Parton and the folks from 9 to 5. Eclectic, too - from Liza Minnelli to the 1980s hair-metal band Poison celebrating with the cast of Rock of Ages. Plus, of course, scenes from the nominated best musicals and best musical revivals.

Then there are the celebrity presenters, who include Nicole Kidman, Anne Hathaway, David Hyde Pierce, Jessica Lange, Frank Langella, and Kevin Spacey. When will there be time for thank-you speeches?

"I certainly never thought this would be in the cards," Harris says of his Sunday gig. "All of a sudden it came into my world, and I was ecstatic. It's the biggest night on Broadway, and to be able to helm the ship is amazing. I get an all-access pass. It will be the best seat in the house."

Harris, 35, comes to the Tony job with some experience. He had good notices hosting the 2009 TV Land Awards in April and has done similar work for the Writers Guild, various magic organizations (he's a magic buff), and the Ovation Awards, Los Angeles' theater prizes.

B.T. McNicholl, who put Harris into the Roundabout Theatre Company revival of Cabaret in 2003, says the actor's interest in magic will help him with his Tony duties.

"Neil is a first-rate magician," says McNicholl, associate director of Cabaret. "And I think the timing and concentration that are required of people who successfully practice sleight of hand has served him well in the theater."

For those who know Harris only as the womanizing Barney Stinson on his current CBS sitcom or from his breakout TV role back in the late 1980s and early '90s as Doogie Howser, M.D., the actor's theater career may come as a surprise.

"I suppose the Tonys will show them that I am knowledgeable in the theater," Harris says. "But I am not out to show anyone that I am theater-worthy. Quite frankly, I am happy if the people who are watching in Middle America think that I am the guy from How I Met Your Mother. But what I am passionate about, in person, is theater."

Les Miserables was the first musical Harris ever heard - years ago - on a cassette tape.

"I was going to a theater camp at New Mexico State University," says the Albuquerque-born Harris. "It sounded very operatic, and I didn't quite get it. Then, later, on my first trip to New York, [Les Miz] was the first show that I saw. . . . And to see the show's barricade come rumbling on stage and the turntable spin around, plus the giant flag waving in the background - it was a jaw-dropping moment."

The actor made his Broadway debut in 2002 when director Daniel Sullivan put a replacement cast into the Pulitzer Prize-winning Proof, a new ensemble that included not only Harris, but Anne Heche, Len Cariou, and Kate Jennings Grant. From there, Harris went into Cabaret as its androgynous, flamboyant master of ceremonies.

"That's the beauty of theater," he says. "From role to role, you really get to embody an entirely different world - Proof being super-cerebral, and then getting to follow that up with a stint in what is almost like a Cirque du Soleil show."

Because How I Met Your Mother occupies his time for seven months a year, there is little time for Harris to do stage work. That's why he is grateful for the Tony job and modest about his contribution to the show.

"We really want to make sure that people who watch the show get a good sense of what's there on Broadway," he says. "To spend too much time watching the host dance around and sing a song takes away time from the shows that deserve that [attention]."

Yet the actor is ready to improvise and deal with the unexpected, and McNicholl is confident Harris can pull it off.

"When he was doing Cabaret, his scene partner was the audience," McNicholl says. "And his ability to simultaneously hear them, bounce off them, and drive the show was a joy to watch. So he's been an emcee on Broadway before. I don't see why Sunday night should be any different."