PHILADELPHIA.-The Rosenbach Museum & Library continues to celebrate the work of famed author and illustrator Maurice Sendak — creator of such children's classics as Where the Wild Things Are, In the Night Kitchen and Outside Over There — with Sendak's 80th Birthday Bash: I'll Be You and You Be Me. In honor of Sendak's 60-year career and 80th birthday, the Rosenbach invites museum-goers and fans of Sendak's work to join the party featuring plenty of birthday cake, wine and live music by the West Philadelphia Orchestra, a band with over a dozen musicians of various backgrounds – jazz, classical, experimental, indie – playing klezmer and Balkan-inspired music.

Sendak's birthday bash is presented in conjunction with There's a Mystery There: Sendak on Sendak, the largest and most ambitious exhibition of Sendak's work ever created. Running now through May 3, 2009, this major retrospective of over 130 pieces pulled from the museum's vast Sendak collection – the biggest collection of "Sendakiana" in the world – features original artwork, rare sketches, never-before-seen working materials and exclusive interview footage.

One of the most famous creators of contemporary children's books, Maurice Sendak's work has challenged the norms of children's literature over time and continues to entrance both children and adults to this day. His innovative techniques and honest portrayal of childhood emotion are celebrated worldwide and have earned him several prestigious honors, including the Caldecott Book Medal (1964), the international Hans Christian Andersen Medal (1970), the National Medal of Arts (1996), a Library of Congress "Living Legend" medal (2000), and the Astrid Lindgren Memorial Award for Literature (2003).

Maurice Sendak chose the Rosenbach to be the repository for his work in the early 1970s thanks to shared literary and collecting interests. His collection of nearly 10,000 works of art, manuscripts, books and ephemera, has been the subject of many exhibitions and has been enjoyed by visitors of all ages.