Nielsen, who recently concluded performances in Charles Busch's Die, Mommie, Die! Off-Broadway, succeeds Burton in the Adult Women roles. Burton, a three-time Tony nominee, has been with the Broadway production since Dec. 21 and will play her final performance March 2.

Obie Award winner Nielsen is having a busy spring: She is also set to appear in the Broadway revival of Les Liaisons Dangereuses presented by the Roundabout Theatre Company. Les Liaisons begins Broadway previews April 11 at the American Airlines Theatre.

In addition to Die, Mommie, Die!, Nielsen has appeared in Charles Busch's Our Leading Lady as well as in Betty's Summer Vacation, Crazy Mary, Based on a Totally True Story, Miss Witherspoon, Jackie, The Green Bird and A Streetcar Named Desire.

Nielsen will joins a Spring company that currently includes Tony nominee Jonathan Groff (Melchior), Lea Michele (Wendla), Blake Bashoff (Moritz), Skylar Astin (Georg), Lilli Cooper (Martha), Blake Daniel (Ernst), Brian Charles Johnson (Otto), Emma Hunton (Ilse), Phoebe Strole (Anna), Jonathan B. Wright (Hanschen), Remy Zaken (Thea), and Glenn Fleshler (Adult Men). The ensemble includes Gerard Canonico, Matt Doyle, Eryn Murman and Alexandra Socha.

Based on the 1891 play by Frank Wedekind, Spring Awakening won eight 2007 Tony Awards, including Best Musical. Spring Awakening features direction by Michael Mayer, choreography by Bill T. Jones, book and lyrics by Steven Sater and a score by Duncan Sheik. Songs featured in the Tony-winning score are "All That's Known," "And Then There Were None," "Blue Wind/Don't Do Sadness," "Left Behind," "Mamma Who Bore Me," "My Junk, "The Bitch of Living," "The Dark I Know Well," "The Guilty Ones," "The Song of Purple Summer," "The Word of Your Body," "Those You've Known," "Totally Fucked," "Touch Me," "Whispering" and "The Mirror-Blue Night."

Spring Awakening's cast album recently earned a Grammy Award for Best Musical Show Album.

The musical made its world premiere Off-Broadway at the Atlantic Theater Company in June 2006. Spring Awakening transferred to Broadway the following November, where it continues to play at the Eugene O'Neill Theatre.

For tickets to the Broadway production, call (212) 239-6200 or visit www.telecharge.com.