"The biggest challenge is, in a way, the greatest part about it which is there's just so much great story, and trying to really drill down into what we wanted to tell, what chunk of this couple's life we wanted to focus on," Levenson said.
"It took a long time and we had to give up a lot of our favourite numbers and a lot of our favourite stories to get at the spine of it, always, which is the relationship between Bob and Gwen," he added.
Actors Sam Rockwell and Michelle Williams are seen as Bob Fosse and dancer Gwen Verdon respectively in the show, aired in India on Star World. Levenson feels Bob and Gwen lead a fascinating life.
"We were fascinated by that dynamic, of the fact that they were not necessarily good for one another, but they were great for one another's work and they enabled one another to do their best work and they sacrificed a lot of happiness for that.
"And the question is: was that worth giving up all of that? I think the answer is probably no, but it's hard to say," said the writer, who is in the race along with Joel Fields to win an Emmy in the Outstanding Writing for a Limited Series, Movie, or Dramatic Special category with the series.
Was there ever anyone else for the role apart from Rockwell and Williams?
"No. Sam was part of this from the very, very beginning. From the beginning Sam was our Bob, and then Michelle was the person we spoke to and she was interested and excited and now I really can't imagine anybody else.
"They did so much work to get these parts right. They did dance class and vocal and dialect and then suddenly on day one we showed up on set and they had just dropped into these characters and they never emerged," he said.
( With inputs from IANS )