Question: John Belushi met Dan Aykroyd while working at what Comedy club best known as the first ever on-going improvisational theater troupe based in Chicago.

Context articles: The Blues Brothers
Spies Like Us
Monteith and Rand
The Blues Brothers (film)
Neighbors (1981 film)
The Second City
John Belushi
Tracy Newman
The Land of Gorch
Belushi: A Biography

The Blues Brothers are an American blues and soul revivalist band which was founded in 1978 by comedy actors Dan Aykroyd and John Belushi as part of a musical sketch on "Saturday Night Live."
 Belushi and Aykroyd, respectively in character as lead vocalist "Joliet" Jake Blues and harmonica player/vocalist Elwood Blues, fronted the band, which was composed of well-known and respected musicians.
 The band made its debut as the musical guest on the April 22, 1978, episode of "Saturday Night Live," performing "Hey Bartender."
Spies Like Us is a 1985 American comedy film directed by John Landis and starring Chevy Chase, Dan Aykroyd, Steve Forrest, and Donna Dixon.
 The film presents the comic adventures of two novice intelligence agents sent to the Soviet Union.
 Originally written by Aykroyd and Dave Thomas to star Aykroyd and John Belushi at Universal, the script went into turnaround and was later picked up by Warner Bros. with Aykroyd and Chase starring.
Monteith and Rand are a comedy team who had their own Broadway show at the Booth Theater in 1979, produced by James Lipton, after a successful off-Broadway run.
 Suzanne Rand and John Monteith are graduates of Second City; Suzanne was in the famed company that included John Belushi and Bill Murray in Chicago, and John performed with John Candy, Dan Aykroyd and Gilda Radner in Toronto.
 Monteith and Rand live in New York City where they teach and perform.
The Blues Brothers is a 1980 American musical crime comedy film directed by John Landis.
 It stars John Belushi and Dan Aykroyd as "Joliet" Jake and Elwood Blues, characters developed from "The Blues Brothers" musical sketch on the NBC variety series "Saturday Night Live".
 The film's screenplay was written by Aykroyd and Landis.
 It features musical numbers by rhythm and blues (R&B), soul, and blues singers James Brown, Cab Calloway, Aretha Franklin, Ray Charles, and John Lee Hooker.
 The film is set in and around Chicago, Illinois, where it was filmed.
 It features non-musical supporting performances by John Candy, Carrie Fisher, Charles Napier, and Henry Gibson.
Neighbors is a 1981 American comedy film based on the novel of the same name by Thomas Berger.
 It was released through Columbia Pictures, was directed by John G. Avildsen, and starred John Belushi, Dan Aykroyd, Cathy Moriarty, and Kathryn Walker.
 The film takes liberties with Berger's story, and features a more upbeat ending.
 The screenplay of the film is officially credited to Larry Gelbart, although it was extensively rewritten, to Gelbart's public disapproval.
 Released two and a half months before John Belushi's death, the film marks the actor's last film performance.
The Second City is an improvisational comedy enterprise, best known as the first ever on-going improvisational theater troupe based in Chicago.
 It also has programs that run out of Toronto and Los Angeles.
 The Second City Theatre opened on December 16, 1959, and has since become one of the most influential and prolific comedy theatres in the world.
John Adam Belushi ( ; January 24, 1949 – March 5, 1982) was an American comedian, actor and musician.
 Belushi is best known for his "intense energy and raucous attitude" which he displayed as one of the seven original cast members of the NBC sketch comedy show "Saturday Night Live" ("SNL").
 Throughout his career, Belushi had a close personal and artistic partnership with his fellow "SNL" star Dan Aykroyd, whom he met while they were both working at Chicago's The Second City comedy club.
Tracy Ann Newman is an American television producer, writer and musician.
 Newman is a founding member of the improvisational theater troupe The Groundlings (as is her sister, Laraine Newman).
 She was co-creator and executive producer of the 2001-09 sitcom "According to Jim".
 She is also a singer-songwriter, as well as an original member of The New Christy Minstrels and lead singer of Tracy Newman and The Reinforcements.
 She is the mother of artist/writer Charlotte Dean, with whom she co-directs the live comedy show "Charlotte's Shorts".
The Land of Gorch was a recurring skit that appeared in season one of the American comedy television program "Saturday Night Live," featuring Jim Henson's Muppets.
 Prior to his work for children on "Sesame Street", Henson had created puppetry work, including his show "Sam and Friends", for adult audiences.
 His characters appeared regularly on the late-night comedy television programs, and "The Ed Sullivan Show".
 After "Sesame Street", Henson feared he would become typecast into working on children's television series.
 His talent agent Bernie Brillstein, who represented Gilda Radner, Dan Aykroyd, and John Belushi, helped him transition to "Saturday Night Live".
Belushi: A Biography is an "oral history" biography of John Belushi, written and collaborated by John's widow, Judith Belushi Pisano and co-author Tanner Colby, with an introduction by Dan Aykroyd.
 Filled with anecdotes and interviews from John's personal friends, fellow "Saturday Night Live" alumni, and film co-stars, it is a non-objective, positive portrayal of the actor's life and influence.