Neil Simon plus Peter Rowsthorn equals laughter.
The 11th floor plus the 12th floor equals the 23rd floor. It all adds up to Laughter on the 23rd Floor, the play penned by Simon nearly 40 years after he began his career as a writer for Sid Caesar's landmark 1950s live TV comedy series Your Show of Shows, which was to comedy what the Brill Building or Motown were to pop music or Florence was to Renaissance art.
Simon was one of the youngest in a hand of aces that included Mel Brooks, Woody Allen, Larry Gelbart and Carl Reiner before they left this intense incubator of wit and storytelling to develop their own storied careers.
Simon, who recently turned 87, went on to give the world Barefoot in the Park, The Odd Couple, Plaza Suite, Sweet Charity, The Sunshine Boys, Brighton Beach Memoirs and The Goodbye Girl in a remarkable list of plays, films and musicals.
Magic was made during intense script sessions on the 11th and 12th floors of the NBC TV office building in New York which Simon thinly fictionalised in his 1993 play Laughter on the 23rd Floor.
In the WA premiere, Rowsthorn plays Max Prince, a character modelled on Caesar, the star and producer of a hit comedy show under pressure from the studio suits to rein in the budget, dumb down the jokes and keep an eye out for reds under the showbiz beds in the McCarthyist America of 1953.
Between the tensions of producing an hour of live comedy each week and being pestered by the bosses who fear his humour is too sophisticated for Middle America, Prince is beginning to unravel. As he tries to preserve the integrity of his writers and self- medicates his stress levels with pills and alcohol, they spend their days hurling humorous invective at him and each other.
"It is a great play to be in for me," Rowsthorn says. "He's a bit weird and he's got a bit of depth to him but also he's a bit nutty, but he also must control it.
"A lot of it is comedians' banter, which lightens up the mood. Because of Max's mental state it gets a little absurdist at times. There are lots of one-line zingers, physical humour and absurdist lines."
Gelbart (who went on to write Tootsie and MASH) and Allen (America's most distinctive comedy filmmaker) have often talked about how their styles were influenced by working with Caesar.
Brooks (Blazing Saddles, The Producers) produced a memorable film based on the experience, My Favorite Year. Reiner used it as the basis for his hit 1960s TV series The Dick Van Dyke Show. Laughter on the 23rd Floor is Simon's own love letter to those times.
Simon's alter-ego Lucas Brickman is played by James Sweeny, the narrator who maintains a running commentary on the writing, fighting and antics in the writers' room on the 23rd floor.
Black Swan State Theatre Company artistic director Kate Cherry steers this production, having also done so at the Melbourne Theatre Company in 2002, when Rowsthorn played a different role with Garry McDonald as Max Prince.
The reviewer for The Age, Jim Murphy, wrote: "The continuous stream of one-liners as they ruffle each other's feathers must be the funniest first half-hour of any play. Ignoring the accepted wisdom that one comedian be surrounded by straight men, Simon's writers' room is chock-a-block with quick-witted funny characters and the repartee flows thick and fast."
Rowsthorn cites that MTC production as one of the highlights of an acting career that includes Kath and Kim, Certified Male, Black Swan's The Importance of Being Earnest last year and the new Robert Connelly film Paper Planes, which last month won CinefestOz's inaugural $100,000 Film Prize.
"It was so outstanding working with Garry McDonald because I grew up with Norman Gunston at school and he was one of the people who led me into doing what I do. I'm having trouble getting Garry out of my head as Max Prince. When you watch someone do something for so long you instinctively go into their rhythm and what they did - so I am now just starting to go away from that and find my own feet. The other cast members help do that as well."
For Rowsthorn, clowning around with Damon Lockwood, Stuart Halusz, Humphrey Bower and the other cast members is a nice change from working solo, as he often does as a stand-up comedian.
"I find ensemble work extremely comfortable and enjoyable because stand-up comedy is only me and all the weight is on you," he says. "There is nothing a theatre audience can do; they can't hurt me and they will laugh at things that are not that funny. I went and saw Pirates of Penzance once and everyone was p…ing themselves - I thought 'What's going on here, where have these people come from?'"
Laughter on the 23rd Floor is at the State Theatre Centre from Saturday to September 21.