Question: "Purple Rain-Union" is the sixth episode of the fourth season of the animated comedy series "Bob's Burgers" and the overall 51st episode, the title of the episode is a reference to the song, film, and which sixth studio album by American recording artist Prince, the first to feature his band The Revolution, and is the soundtrack to the 1984 film of the same name?
Context: "Purple Rain-Union" is the sixth episode of the fourth season of the animated comedy series "Bob's Burgers" and the overall 51st episode, and is written by Loren Bouchard and Nora Smith and directed by Tyree Dillihay.  It aired on Fox in the United States on December 1, 2013.  The title of the episode is a reference to the song, film, and album "Purple Rain" by Prince. "The Hauntening" is the third episode of the sixth season of the American animated comedy series "Bob's Burgers" and the 91st episode overall.  It was written by Steven Davis and Kevin Yu who won an Annie Award, and was directed by Jennifer Coyle.  Guest star is Max Greenfield who voices boyband member Boo Boo.  It firsy aired in the United States on October 18, 2015 at Fox Network.  In this episode, the Belcher family goes to a haunted house on Halloween, where the parents want to scare their children, especially Louise. "The Quirkducers" is the sixth episode of the seventh season of the animated comedy series "Bob's Burgers" and the overall 113th episode, and is written by Steven Davis and Kelvin Yu and directed by Mauricio Pardo.  It aired on Fox in the United States on November 20, 2016.  In the episode, Gene and Louise decide to sabotage the annual Thanksgiving play to save their long weekend, but Tina provides her fan fiction as the subject matter, leading the kids to work on their own version.  Meanwhile, Linda finds a potato that resembles her deceased grandfather. The Purple Rain Tour was the fifth concert tour by American recording artist Prince and The Revolution following up on the success of his sixth studio album "Purple Rain" and his 1984 film "Purple Rain".  According to "Spin", the tour sold over 1.7 million tickets. "I Get Psy-chic Out of You" is the 16th episode of the fourth season of the animated comedy series "Bob's Burgers" and the overall 61st episode, and is written by Jon Schroeder and directed by Chris Song.  It aired on Fox in the United States on April 6, 2014. "The Cook, the Steve, the Gayle, & Her Lover" is the sixth episode of the sixth season of the animated comedy series "Bob's Burgers" and the overall 94th episode, written by Nora Smith and directed by Tyree Dillihay.  It aired on Fox in the United States on January 17, 2016.  When Bob throws a dinner party to bond with his new friend, Gayle uses the opportunity to introduce the family to her new love interest.  Little does she know, Louise has a long-standing feud with Gayle’s boyfriend and her niece will stop at nothing to break them apart.  Calamity ensues as Bob attempts to impress his new buddy and the kids take action. "Dawn of the Peck" is the fourth episode of the fifth season of the animated comedy series "Bob's Burgers" and the overall 71st episode.  It was written by Lizzie Molyneux and Wendy Molyneux and directed by Tyree Dillihay.  It aired on Fox in the United States on November 23, 2014. Purple Rain is the sixth studio album by American recording artist Prince, the first to feature his band The Revolution, and is the soundtrack to the 1984 film of the same name.  It was released on June 25, 1984 by Warner Bros.  Records.  To date, it has sold over 25 million copies worldwide, making it the third-best-selling soundtrack album of all time. "Wag the Hog" is the 13th episode of the sixth season of the American animated comedy series "Bob's Burgers" and the 101st episode overall.  It was directed by Brian Loschiavo and written by Holly Schlesinger.  Its guest stars are Robert Ben Garant as Critter, Wendi McLendon-Covey as Mudflap, Sarah Baker as Bethany, Joe Lo Truglio as Carl, Thomas Lennon as Kenny and Melissa Bardin Galsky as Candace.  It aired in the United States on Fox Network on April 10, 2016.  In this episode, Bob Belcher and his children try to get Critter out of prison by selling his motorcycle to the investment banker Kenny while Linda Belcher babysits Critter's and Mudflap's son Sidecar. "Father of the Bob" is the sixth episode of the fifth season of the animated comedy series "Bob's Burgers" and the overall 73rd episode, and is written by Steven Davis and Kelvin Yu and directed by Chris Song.  It aired on Fox in the United States on December 7, 2014.
Answer: Purple Rain