Audiences will remember him from the T-V series “Trapper John, M-D,” but Gregory Harrison is starring as the male lead in the musical “Chicago” on the stage in Des Moines this week. The 54-year-old actor has had a long career in T-V, film and theatre and says the live Broadway musical is his favorite. Harrison says “Theatre is really the purest form of my craft and what I trained to do…and it’s what pleases me the most. I’m glad to be doing this show right now and I love going into the theatre every night and making magic with the audience.” He’s starred in over 40 movies-of-the-week. The latest two were record breakers; “First Daughter” for T-B-S was viewed by the largest movie audience of all time for basic cable and “Au Pair” was the most watched program in the 22-year history of the Family Channel.While the musical “Chicago” has been around many years, the movie verision in 2002 was a blockbuster. Millions of Americans have already seen the screen version story but Harrison says if people haven’t seen it on stage, they’re missing out. He says the movie brought out the gritty, seedy, dark tale of crime and prison. Harrison says the theatre version is the same story but that’s all it has in common. The choreography is very different, the music is similar but there are more songs in the Broadway version — “and it’s a heck of a lot funnier, faster paced, and it’s important for the audience to know this is a really jolly experience.” The show runs through Sunday at the Civic Center of Greater Des Moines at “”.