'Smash': Tom Sings the Marilyn Monroe Blues (Exclusive Video)

Christian Borle steps in to play studio boss Darryl Zanuck during rehearsals for "Bombshell" in an exclusive clip from Monday's episode.
"Smash's" Christian Borle

When the actor playing Darryl Zanuck fails to make it to rehearsals on Monday's episode of Smash, Christian Borle's Tom will step in to save the day.

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During Monday's "Understudy" episode, the Broadway veteran takes his turn in the rehearsal spotlight during a musical number in which the beleaguered studio chief sings the Marilyn Monroe blues as part of the newly titled Bombshell play at the center of the NBC series.

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"She makes directors wait all day; one line per hour is all she'll say and still she thinks we're going to pay? She needs a talking to," he sings to a clearly entertained ensemble.

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Elsewhere, Tom isn't the only one filling in for an absent star when Uma Thurman's Rebecca Duvall gets stuck in Cuba en route to join the New York production, forcing Derek (Jack Davenport) to put Karen (Katharine McPhee) into Marilyn's shoes.

Check out the clip, exclusive to The Hollywood Reporter, to see how Derek responds to rival Tom's performance.

What do you think of Tom's effort? Smash airs Mondays at 10 p.m. on NBC.

E-mail: Lesley.Goldberg@thr.com; Twitter: @Snoodit