I've learned to keep my work on the stage or on the screen.

I was a Hollywood musical fan as a kid, and I know how rare it is for someone who originates the Broadway role to get to then do it on screen.

It was a surprise to me and a happy accident that it was such a skill [natural falsetto] - a latent skill and that there was a way to exploit it. And it was a key to playing great role Frankie Valli in such a huge show.

I think one of the ways that these young singers got started is that they would end up in clubs. And a lot of them were mafia owned. And so there was almost an unspoken kind of mafia sponsorship, which is just a very interesting part of that area's music history.

When you look at sort of pop stardom now, some of these singers, it seems like the idea of them was created in a marketing meeting, and then they just found someone to sort of fulfill that role.

It was great to play for a live audience on a stage.

But when you get to know a character so well, you start to have insights that you can't show because you're confined to your script of your hit show.