It was announced by NBC today that there will be seven guest stars on the finale of 30 Rock this season. The following stars will make their appearance on May 14, 2009.

Information on each star is from Wikipedia, the free, on-line encyclopedia.

Alan Alda (born January 28, 1936) is an Academy Award-nominated, Emmy award-winning actor, director and screenwriter. He is well-known for his role as “Hawkeye Pierce” in the television series M*A*S*H. During the 1970s and ’80s, he was viewed as the archetypal sympathetic male, though in recent years, he has appeared in roles that counter that image.

Sherri Shepherd worked a day job as a legal secretary while doing stand-up comedy at night. Her first TV role was on the show, Cleghorne!, starring former Saturday Night Live cast member, Ellen Cleghorne. Three years later, Shepherd pursued acting and stand-up comedy full-time, working again as a legal secretary for a day job. Perhaps her most successful role prior to The View, was playing the main character of Ramona Platt (2002-2006) on the comedy Less Than Perfect (Seasons 1-4, 81 episodes) as a co-worker friend.

Sheryl Suzanne Crow (born February 11, 1962) is an American singer-songwriter and musician. Her music blends rock, country, pop and folk, into one mainstream sound, and she has won nine Grammy Awards. Crow is also a political activist.

Mary Jane Blige (born January 11, 1971), more commonly known as Mary J. Blige, is an American recording artist, record producer and actress. She has sold more than forty eight million albums worldwide. She has received over twenty-six Grammy Award nominations for her work, winning nine, and has been awarded the World Music Legends Award for combining hip hop and soul together.

Elvis Costello is an English singer-songwriter. He came to prominence as an early participant in London’s pub rock scene in the mid-1970s, and later became associated with the punk rock and New Wave musical genres, before establishing his own unique voice in the 1980s. Steeped in wordplay, the vocabulary of Costello’s lyrics is broader than that of most popular songs. His work has drawn on many diverse musical genres.

Adam Noah Levine (born March 18, 1979) is an American singer-songwriter and guitarist. He is the frontman for the pop rock band Maroon 5.

Levine has stated in various interviews that he does not plan on continuing in Maroon 5 forever, and may stop after the tour for Maroon 5′s probable third album.

Clay Aiken (born Clayton Holmes Grissom on November 30, 1978) is an American pop singer who began his rise to fame on the second season of the television programAmerican Idol in 2003. RCA Records offered him a recording contract, and his multi-platinum debut album Measure of a Man was released in October 2003. He released four more albums on the RCA label: Merry Christmas with Love, A Thousand Different Ways, and the Christmas EP, All is Well. His fourth studio album (the first album of original material since 2003′s Measure of a Man), On My Way Here was released on May 6, 2008.

In the years following his American Idol appearance, Aiken has launched eight tours, authored a New York Times best-selling book Learning to Sing: Hearing the Music in Your LifeA Clay Aiken Christmas. He has been a frequent talk show guest, particularly on The Tonight Show and Jimmy Kimmel Live. He appeared as a guest star on Scrubs and participated in comedy skits on Kimmel and Saturday Night Live. with Allison Glock, and was the executive producer for a 2004 televised Christmas special,

Aiken created the Bubel/Aiken Foundation in 2003, accepted a UNICEF ambassadorship in 2004, and in 2006 was appointed for a two-year term to the Presidential Committee for People with Intellectual Disabilities.

Aiken made his Broadway debut playing the role of Sir Robin in Monty Python’s Spamalot in January 2008. His run ended in May but he rejoined the cast as Sir Robin in September and remained through January 4, 2009.

It is exciting to see the wonderful stars that have been picked for the 30 Rock finale. Clay is in good company.