Question: In the Glee episode "Bad Reputation," Sue Sylvester dances to this song, by a four-time Grammy winner and star of musical film "Grease."

Olivia Newton-John, (born 26 September 1948) is an Australian singer, songwriter, actress, entrepreneur and activist.  Eleven of her singles (including two platinum) and fourteen of her albums (including two platinum and four double platinum) have been certified gold by the RIAA.  She has sold an estimated 100 million records worldwide, making her one of the world's best-selling artists of all time.  She starred in the musical film "Grease", and is one of the most successful in history, with the single You're the One That I Want, with John Travolta, one of the best selling singles.  She is a four-time Grammy award winner who has amassed five number-one and ten other top ten "Billboard" Hot 100 singles, and two number-one "Billboard" 200 solo albums. <SEP> "The Rocky Horror Glee Show" is the fifth episode of the second season of the American television series "Glee", and the twenty-seventh episode overall.  It was written by Ryan Murphy, from a story by Murphy and Tim Wollaston, directed by Adam Shankman, and premiered on Fox on October 26, 2010.  The episode features the glee club paying tribute to the 1973 musical "The Rocky Horror Show", with elements of its 1975 film adaptation "The Rocky Horror Picture Show", by staging it as a school musical.  While cheerleading coach Sue Sylvester (Jane Lynch) attempts to sabotage the production, glee club director Will Schuester (Matthew Morrison) dwells on his feelings for guidance counselor Emma Pillsbury (Jayma Mays), and club members Finn (Cory Monteith) and Sam (Chord Overstreet) deal with body image issues.  Barry Bostwick and Meat Loaf, who star in the original film, appear in cameo roles in this episode. <SEP>  The episode premiered on the Fox network on May 4, 2010.  It was directed by Elodie Keene, and written by series creator Ian Brennan.  In "Bad Reputation", cheerleading coach Sue Sylvester (Jane Lynch) is publicly ridiculed when a video of her dancing to Olivia Newton-John's "Physical" is posted on YouTube.  A salacious list about members of the glee club circulates the school, leading certain members to try to earn themselves a bad reputation.  Newton-John guest-stars as herself in the episode, and Molly Shannon makes her first appearance in a recurring role.  Following their romance in the episode "Mash-Up", club members Rachel (Lea Michele) and Puck (Mark Salling) are reunited, a decision made by the producers due to the unexpected popularity of the pairing. "Bad Reputation" is the seventeenth episode of the American television series, "Glee". <SEP> "Mash Off" is the sixth episode of the third season of the American musical television series "Glee", and the fiftieth overall.  The episode was written by Michael Hitchcock and directed by Eric Stoltz, and originally aired on Fox in the United States on November 15, 2011.  Special guest star Idina Menzel is featured as rival glee club director Shelby Corcoran, and she and Will Schuester (Matthew Morrison) hold a mash-up competition between the Troubletones and the New Directions.  Santana (Naya Rivera) mercilessly taunts rival glee club member Finn (Cory Monteith), who ultimately responds by publicly accusing her of cowardice in her relationship with Brittany, thereby revealing to their fellow students that she is a lesbian.  Sue Sylvester (Jane Lynch) starts a propaganda campaign against Burt Hummel (Mike O'Malley), her chief rival in the special election for congress.