Stephanie Pfriender Stylander Gregory Harrison Click photo for larger image. "Chicago" Where: PNC Broadway Across America at Heinz Hall. When: 7:30 p.m. Tuesday-Thursday, 8 p.m. Friday, 2 and 8 p.m. Saturday, and 1 p.m. and 6:30 p.m. next Sunday. Tickets: $20-$58.50; 412-392-4900 or http://pgharts.org.

Actor Gregory Harrison has been living with the role of one of musical theater's most memorable schemers -- "Chicago" lawyer Billy Flynn -- off and on since 2003.

Harrison has logged more than 1,000 performances, both on Broadway and in the touring production, and this is his second engagement in Pittsburgh, although last time he only did half the "Chicago" run here. This time, he'll perform throughout the six-day run, which opens Tuesday at Heinz Hall. The production also stars Melba Moore as Matron Mama Morton, Michelle DeJean as Roxie Hart and Terra C. MacLeod as Velma Kelly.

It has been an ideal arrangement, Harrison says: He's been able to jump in for a few weeks and leave the show when other projects come up.

"There are several Billy Flynns who spell each other. I've worked with any one of the Velmas or Roxies or Mama Mortons, either on Broadway or on the tour, so we have a real shorthand with each other. I got a call a few weeks ago, and I said, 'Absolutely, I'd love to come back.'"

Even after more than three years, the actor is still enthusiastic about playing Flynn, whom he sees as a "very manipulative and ruthless character. But he should be performed as charming and likable and benevolent, [with] the ruthless manipulative stuff under the surface."

Living with a character for a long time constantly reveals new facets, Harrison says. "I always feel like I think I've done everything with the role, and then I discover that I haven't. I discover something fuller or more interesting, or I find a joke I didn't realize was there.

"The performance as a whole evolves. We encourage each other to evolve. It keeps it interesting."

Listen In: Gregory Harrison talks with the PG's Adrian McCoy about his upcoming appearance in "Chicago": On how "Chicago" resonates with audiences What's it's like to perform the same role again and again The psychology of Billy Flynn's character Harrison's love of surfing, especially in Hawaii

The John Kander/Fred Ebb musical -- and its razzle-dazzle tale of crime and celebrity -- continues to enjoy a record run. Harrison sees plenty of reasons for its longevity and appeal.

"It works on so many levels. Musically it's one of the best scores ever written for American musicals. The choreography is [Bob] Fosse-style, and that's always interesting and compelling to watch.

"The subject matter itself resonates more today" than when the show premiered in 1975, he says. "It's basically a satire about what people are willing to do to be famous. If you watch television any night of the week, you get a lesson in just how far people are willing to go for their five minutes."

Some people still associate Harrison with TV and his role as surgeon Gonzo Gates on "Trapper John, M.D." He spent seven seasons on the CBS series, which debuted in 1979.

But unlike some actors who resent being associated with a character, Harrison says, "I got out of 'Trapper John' so long ago that anyone under 30 doesn't have a clue what that was. There's a whole new generation or two ... who just have a perplexed look on their face if someone says, 'Hey, Gonzo.'"

	Paul Kolnik Gregory Harrison in "Chicago," coming to Heinz Hall this week. Click photo for larger image.

He has continued to work in TV since, including series such as "Ed," "Judging Amy," "Law and Order: SVU" and "Joey."

Harrison, who started his career as an aspiring singer and songwriter, made a natural leap to musical theater and stage productions -- "Steel Pier," "Follies" and "Guys and Dolls" among them. His credits are a long juggling act of stage and screen roles, directing and producing. "I've always loved the combination of mixing theater with film work and television. And I've always been interested in music. They overlap in many ways.

"But there are huge differences between doing theater and doing film, and I love those differences. I miss film if I've been on stage for too many months without getting in front of a camera. The craft is very different and asks different things of you."

When Harrison isn't working, he enjoys another lifelong passion -- surfing. "No matter how old I get or how far I am from the ocean for lengths of time, I'm always drawn back to it. I'm an island boy" -- he was born on Santa Catalina Island, Calif. -- "and I'm going to stay an island boy for the rest of my life."

Pittsburgh doesn't have the big waves, but Harrison has other plans for his free time here.

"I'm bringing my golf clubs because I just watched the U.S. Open [held at Oakmont Country Club], and I'm anxious to play golf around Pittsburgh."