Saying goodbye to "Will and Grace" after eight seasons was tough for Debra Messing.

"That last night was brutal. It was like 7-year-olds crying," she said after the show's series finale.

Just as tough as ending was deciding to start on another series.

"I'm a mom and it has to be really, really special for me to commit to something," Messing says now.

"Smash" turned out to be that really special something.

"I called my agents, and I said, 'I have to be a part of this,' and they said, 'Who is this?' because that's not in my personality," she laughs.

It wasn't simply her own role of Julia, a successful Broadway songwriter, but the array of other talents involved with this insider's look at the making of a musical.

"It's insanity. From the creative team to the cast, everywhere you turn there's another person who's expert at what they do," Messing says.

That includes real-life Broadway veteran Christian Borle, who plays Messing's longtime song-writing partner.

Messing says she's enjoyed shooting scenes for "Smash" all around New York.