Title: Jeff Conaway
Content:  The following year, Conaway appeared in the original cast of the Broadway musical Grease, as an understudy to several roles including that of the lead male character, Danny Zuko, and eventually succeeded role-originator Barry Bostwick. He played the role for 2 1/2 years while his friend John Travolta, with whom he shared a manager, later joined the show, playing the supporting role of Doody. The two would reunite in the 1978 motion picture musical Grease, in which Travolta played Zuko and Conaway his buddy Kenickie. After breaking into series television in 1975 with Happy Days, followed by guest spots in several other TV shows, and three more movies including 
Title: Jeff Conaway
Content:  Jeffrey Charles William Michael Conaway (October 5, 1950 – May 27, 2011) was an American actor and singer. He was known for playing Kenickie in the movie Grease and for his roles in two American television series: struggling actor Bobby Wheeler on Taxi and security officer Zack Allan on Babylon 5. Conaway was also featured in the first and second seasons of the reality television series Celebrity Rehab with Dr. Drew.
Title: Jeff Conaway
Content:  Conaway was married three times. His first, short-lived marriage (when he was 21) was to a dancer he had been seeing for two years. It was annulled. His second marriage, from 1980 until their divorce in 1985, was to Rona Newton-John, elder sister of his Grease co-star, Olivia Newton-John. His stepson, Emerson Newton-John, is a race car driver. His third marriage was to Kerri Young from 1990 to 2000.
Title: Jeff Conaway
Content:  filming the "Greased Lightning" scene, which had been exacerbated recently by lifting boxes in his home, and he had turned to substances to manage the pain. Conaway's appearance on the show's first and second seasons drew much attention because of his severely crippled state, his constant threats to leave the facility, and his frequent inability to speak clearly. Upon arrival at the Pasadena Recovery Center (which was filmed as part of Celebrity Rehab's first episode) Conaway, using a wheelchair, arrived drunk, mumbling to Drew Pinsky that the night before he had binged on cocaine and Jack Daniel's whiskey. During the second episode of Celebrity Rehab's first season, Conaway, fed up with his back pain, withdrawal symptoms, 
Title: Jeff Conaway
Content:  While at NYU, he appeared in television commercials and had the lead in a school production of The Threepenny Opera. He made his movie debut in the 1971 romantic drama Jennifer on My Mind, which also featured future stars Robert De Niro and Barry Bostwick.
Title: Grease (film)
Content: Jeff Conaway as Kenickie, Danny's best friend, Rizzo's boyfriend and the owner of Greased Lightnin’ ; Barry Pearl as Doody, a member of the T-Birds, who pairs with Frenchy at the school dance ; Michael Tucci as Sonny LaTierri, a trouble-making womanizer-wannabe and a T-Bird, who courts Marty with little success over the course of the film ; Kelly Ward as Putzie, a member of the T-Birds whose relationship with Jan builds over the course of the film 
Title: Jeff Conaway
Content:  to perform. Conaway's dialogue for that episode was divided between his co-stars Danny DeVito and Christopher Lloyd, who delivered the jokes well enough so that Conaway's absence had little negative effect on the episode. This development caused the show's producers to realize that Conaway was expendable and contributed to his termination. Conaway was reported at the time to be dissatisfied with being typecast as a "blond bimbo" and the "butt of struggling-actor jokes," along with finding the nature of the role repetitive. He also felt creatively stymied: "I wanted to do things with Bobby, but as the show went on, I could see I wasn't going to get that 
Title: Jeff Conaway
Content:  Conaway took courses and auditing from the Church of Scientology to cope with his drug problem and depression, although he did not intend to become a Scientologist. In June 2009, Conaway joined Celebrity Rehab castmate Mary Carey at the premiere of her parody film Celebrity Pornhab with Dr. Screw. In August 2009, Conaway was interviewed by Entertainment Tonight. In the interview, the actor claimed he was much better after a fifth back operation, and that he had yet to use painkillers again. He also discussed unscrupulous doctors and enablers. In March 2010, shortly after the death of actor Corey Haim, Conaway told E! News that he had warned Haim about dying because of prescription drug abuse.
Title: Grease 2
Content:  Birch proposed an idea to feature Travolta and Newton-John reprising their characters as a now married couple running a gas station near the end of the film, with Travolta to sing a new number "Gas Pump Jockey;" this did not come to fruition. Paramount tried to get Jeff Conaway and Stockard Channing from the first film to do cameos but this did not happen (Channing, by then 37 years old, had left Hollywood for a time in the early 1980s to focus on her stage career). Early plans for Grease 2 had Conaway and Channing's characters, Kenickie and Rizzo, as main characters 
Title: Jeff Conaway
Content:  set in Knoxville, Tennessee, the 10-year-old Conaway landed a featured role as one of four boys. The 1961 Pulitzer Prize-winning play was nominated for a Tony Award for Best Play and ran 333 performances and one preview from November 29, 1960, to September 16, 1961. Conaway remained for the entire run, then toured with the national company of the play Critic's Choice. Conaway worked as a child model, and attended high school at the Quintano School for Young Professionals. After playing with the rock band 3 1/2 beginning at age 15, he attended the North Carolina School of the Arts and later transferred to New York University.

Question: what part did jeff conaway play in grease?
Answer: Kenickie Murdoch.