Bill Irwin is a clown. But please, don't think of that as a slam. In fact, it's the highest praise we can lay on the elastic-bodied comic, who began his career in the Pickle Family Circus back in the '70s, but by the early '80s had become a wonderfully weird presence in the New York theater world. Movies and TV would soon call for Irwin's modern-day Buster Keaton shenanigans, but would rarely utilize the full arsenal of his talents. Happily though, he's currently prepping to star in Broadway's Who's Afraid of Virgin Wolfe and gets a loving tribute tonight on PBS's Great Performances (check TV Guide listings). "Bill Irwin, Clown Prince" is a behind-the-scenes look at Irwin and his craft that proves what we've always suspected: Being a clown ain't always a load of laughs.

TV Guide Online: This special offers a very intimate peek into the work behind your art.
Bill Irwin:
To be honest, I don't think I would have felt comfortable with anyone else except PBS following me around so closely.

TVGO: People may not know much about clowning. Who are currently some of your favorite practitioners?
As for traditional shows, I like current headliners in Ringling Brothers like Bello Nock and David Larible. They have my undying admiration because they sometimes do 12 shows a week.

TVGO: What about Cirque Du Soleil?
Well, Cirque Du Soleil has re-invented the circus — for better or worse. My hope is that clowning doesn't get lost, but I haven't been able to see the current underwater show in Vegas.

TVGO: What do most people recognize you from?
Northern Exposure. Which delights and surprises me because I only did two episodes as a character known as "The Flying Man." And kids between the ages of two and four know me as Mr. Noodle from Sesame Street.

TVGO: I figured folks would best know you from dancing with Robin Williams and Bobby McFerrin in that '80's video for "Don't Worry, Be Happy."
Ah yes, I was in an elevator in New York with a bunch of cops who were responding to an alarm going off. And as they exited the elevator with their guns drawn, ready to meet the enemy, one turned to me and said, "Hey, I remember you from the Bobby McFerrin video." (Laughs) It just seemed like an odd time to be thinking about music videos.

TVGO: Tell us about your long friendship with Robin Williams.
We met doing the movie Popeye, and he's been a generous guy and really helped me along with doing improvisation. When we worked together with Steve Martin in the play Waiting for Godot, I remember during rehearsals, Robin did a Jane Goodall impression. Then, [he] went and bowed at Steve Martin's feet and started calling him the "Alpha Comedian," which just broke Steve up. And if you can break Steve up, that's quite an accomplishment.

TVGO: Do you like Jim Carrey's work?
Oh yeah, I worked with him in The Grinch and my admiration for him really grew during that. I think his acting in Eternal Sunshine of the Spotless Mind is just incredible. It would be fantastic to see Jim and Robin together on screen.

TVGO: In this PBS show, you say growing older isn't easy for a clown.
There are lots of aches and pains now, but I don't want to dwell on it. Besides the physical, there's another question to deal with, because a lot of the clown tradition is doing anything to get the girl. A 30-year-old comic who will do anything to get the 25-year-old girl is funny and inspiring, but the 55-year-old comic who will do anything to get the 25-year-old girl is kind of... well, icky.

TVGO: Does the prospect of being an old clown bring you down?
Hmm... I'm never going to fall down the staircase the way a younger guy does. So, at some point, you just have to give that over to them — but remember, I can always be the one to push them down the stairs.