Ralph was the original Deena Jones in Broadway's Dreamgirls, for which she was Tony Award-nominated in 1982 as Best Actress in a Musical. Hudson won the Best Supporting Actress Academy Award in 2007 for playing Effie in the film "Dreamgirls."

Ralph also created the role of Muzzy in Broadway's Thoroughly Modern Millie and has starred in films ("The Mighty Quinn") and TV series ("Moesha," "Designing Women," "It's a Living").

Vulture.com was the first to report the Ralph news. Playbill.com was able to confirm that Ralph will play Cynthia, who is not an actress or performer but is the mom of Hudson's stage star Veronica Moore. Hudson is set to appear in a multi-episode arc on "Smash," including early episodes in season two.  Both are new to the series, which is expected to be significantly revamped when it surfaces on NBC in midseason (think January). Josh Safran ("Gossip Girl") is the new show runner in charge of story, replacing creator Theresa Rebeck. Tony nominee Sean Hayes, Tony nominee Jeremy Jordan, Andy Mientus and Tony nominee Daniel Sunjata are among the other newcomers to the cast in season two.

The show — a soap opera about the making of a new musical called Bombshell, about Marilyn Monroe — offered mother-daughter tension in season one: Rising star Ivy (played by Megan Hilty) sparred with her Broadway star mom, Lee (played by Tony winner Bernadette Peters). Stay tuned.

Episodes of season one of "Smash" are available for live streaming on NBC.com.

Did you follow Playbill.com's weekly episode-by-episode recap, The Smash Report? Here's the May 2012 column that looks at the season-one finale.