In show business, a guest appearance is the participation of an outsider performer (such as a musician or actor) in an event such as a music record or concert, show, etc., when the performer does not belong to the regular cast, band or other performing group.
 In music, such an outside performer is often referred to as a guest artist.
 In performance art, the terms guest role or guest star are also common, the latter term specifically indicating the guest appearance of a celebrity.
 The latter is often also credited as "special guest star" or "special musical guest star" by some production companies.
Dead 7 (formerly titled Dead West) is an American post-apocalyptic zombie horror western film written by Nick Carter, American singer best known as a member of the Backstreet Boys.
 It is directed by Danny Roew and produced by The Asylum.
 The movie aired on SyFy on April 1, 2016 in the United States.
 Carter managed to get two of his bandmates, A. J. McLean and Howie Dorough to star in the movie.
 In addition, Carter also cast several members from other boy bands like 98 Degrees, O-Town, 'N Sync and All-4-One.
 A free copy of the theme song "In the End" was released on March 28, performed by band members Nick Carter, AJ McLean and Howie D.; Joey Fatone and Chris Kirkpatrick from NSYNC; Jeff Timmons from 98 Degrees; and Erik-Michael Estrada from O-Town.
NSYNC (sometimes stylized as *NSYNC or 'N Sync) was an American boy band formed in Orlando, Florida in 1995 and launched in Germany by BMG Ariola Munich.
 NSYNC consisted of Justin Timberlake, JC Chasez, Chris Kirkpatrick, Joey Fatone, and Lance Bass.
 After heavily publicized legal battles with their former manager Lou Pearlman and former record label Bertelsmann Music Group, the group's second album, "No Strings Attached", sold over one million copies in one day and 2.42 million copies in one week, which was a record for over fifteen years.
 Among the group's singles, "Bye Bye Bye", "This I Promise You", "Girlfriend" and "It's Gonna Be Me" reached the top 10 in several national charts, with the latter being a US "Billboard" Hot 100 number one.
 In addition to a host of Grammy Award nominations, NSYNC has performed at the World Series, the Super Bowl and the Olympic Games, and sang or recorded with Elton John, Stevie Wonder, Michael Jackson, Phil Collins, Celine Dion, Aerosmith, Nelly, Left Eye, Mary J. Blige, country music supergroup Alabama, and Gloria Estefan.
"Lisa the Drama Queen" is the ninth episode of the twentieth season of "The Simpsons".
 It originally aired on the Fox network in the United States on January 25, 2009 and guest starred Emily Blunt as Juliet.
 A special version of the end credits theme was performed by Fall Out Boy, although they do not guest star in the actual episode.
 This was the last episode in the series to be presented only in standard definition, the first regular episode to begin right after the opening credits without a commercial break, with an episode now having four segments, and the last episode to use the original opening sequence starting from Season 2.
 Brian Kelley returns as a writer after five seasons of being absent from the show.
 The episode is very loosely based on the 1994 film "Heavenly Creatures".
Mark Matkevich (born June 19, 1978) is an American art gallerist and actor best known for appearing as Drue Valentine in 17 episodes of the television program "Dawson's Creek".
 He also appeared in the hit romantic comedy, 'Sweet Home Alabama', and played Patrick Dempsey's best friend 'Tom Darovsic'.
 Matkevich has also had recurring roles on "Ed" and "Joan of Arcadia".
 He played Dan, a medical student, in an episode of "Tru Calling" (episode entitled "Haunted") and had a guest star role in Season 5 (series five) of "NCIS".
 He has appeared in the Showtime show "Dexter" with Michael C. Hall.
 He also was a guest star on "Drake & Josh" in an episode entitled "Guitar," where he plays rock guitarist Devin Malone for whom Drake substitutes in a concert after Josh accidentally breaks the hand of Mark Matkevich's character.
"New Kids on the Blecch" is the fourteenth episode of the twelfth season of "The Simpsons".
 It first aired on the Fox network in the United States on February 25, 2001.
 In the episode, a music producer selects Bart, Nelson, Milhouse and Ralph to be members of the next hit boy band, who record songs containing subliminal messages about joining the Navy.
"Together Again" is a song by American boy band NSYNC.
 It was released as the fifth single from their self-titled debut album.
 It was released in November 1997 exclusively on the German market.
 It was written by Andy Reynolds and Tee Green and is one of the few NSYNC songs where Joey Fatone and Chris Kirkpatrick each sing a verse.
 The single has never been released worldwide.
 It was the group's first and only release to include a video for the track.
Christopher Alan Kirkpatrick (born October 17, 1971) is an American singer, dancer, and voice actor who is best known for his work as a founding member of the pop group NSYNC, in which he sang countertenor.
 He has provided voices for numerous kids shows, including the voice of Chip Skylark on "The Fairly OddParents".
 He also guest starred on "The Simpsons" as himself, along with his fellow NSYNC bandmates, in the episode "New Kids on the Blecch".
The "WWE Raw" guest star is a concept which involves a current or former WWE performer, mainstream celebrity or, sports personality making a guest appearance, assuming the on-screen role as a guest star for that particular episode.
 The guest star also often participates in backstage vignettes with members of the WWE roster.
"Wonder-ful" is the twenty-first episode of the fourth season of the American musical television series "Glee", and the eighty-seventh episode overall.
 It aired on Fox in the United States on May 2, 2013, and features the introduction of special guest star Katey Sagal as Nancy Abrams and the return of special guest star Kate Hudson as Cassandra July.
 The episode is a tribute to the music of Stevie Wonder.

Question: In what season of "The Simpsons" did Chris Kirkpatrick guest star in an episode?
Answer: the twelfth season