Question: In which season was the artist of Ballerina Girl a guest judge on American Idol?

full_context: Document 1: American Idol: Once in Hollywood, the contestants perform individually or in groups in a series of rounds. Until season ten, there were usually three rounds of eliminations in Hollywood. In the first round the contestants emerged in groups but performed individually. For the next round, the contestants put themselves in small groups and perform a song together. In the final round, the contestants perform solo with a song of their choice a cappella or accompanied by a band‍—‌depending on the season. In seasons two and three, contestants were also asked to write original lyrics or melody in an additional round after the first round. In season seven, the group round was eliminated and contestants may, after a first solo performance and on judges approval, skip a second solo round and move directly to the final Hollywood round. In season twelve, the executive producers split up the females and males and chose the members to form the groups in the group round.
Document 2: Love Will Conquer All: ``Love Will Conquer All ''is a track from Lionel Richie's 1986 album`` Dancing on the Ceiling'' featuring Marva King on backing vocals. The song was written by Richie along with Greg Phillinganes and Cynthia Weil. ``Love Will Conquer All ''was Richie's tenth number one on the Adult Contemporary chart. The single spent two weeks at number one and peaked at number nine on the Billboard Hot 100.`` Love Will Conquer All'' also went to number two for two weeks on the soul chart, behind ``Tasty Love ''by Freddie Jackson.
Document 3: Encore (Lionel Richie album): Encore is the first live album by Lionel Richie, released on November 26, 2002. Various international versions also included "Goodbye", "To Love a Woman" (featuring Enrique Iglesias), "Don't Stop the Music" and "Tender Heart". The material on the album was recorded at Wembley Arena in London, England in May 2001.
Document 4: American Idol: In season eight, Latin Grammy Award-nominated singer–songwriter and record producer Kara DioGuardi was added as a fourth judge. She stayed for two seasons and left the show before season ten. Paula Abdul left the show before season nine after failing to agree terms with the show producers. Emmy Award-winning talk show host Ellen DeGeneres replaced Paula Abdul for that season, but left after just one season. On January 11, 2010, Simon Cowell announced that he was leaving the show to pursue introducing the American version of his show The X Factor to the USA for 2011. Jennifer Lopez and Steven Tyler joined the judging panel in season ten, but both left after two seasons. They were replaced by three new judges, Mariah Carey, Nicki Minaj and Keith Urban, who joined Randy Jackson in season 12. However both Carey and Minaj left after one season, and Randy Jackson also announced that he would depart the show after twelve seasons as a judge but would return as a mentor. Urban is the only judge from season 12 to return in season 13. He was joined by previous judge Jennifer Lopez and former mentor Harry Connick, Jr.. Lopez, Urban and Connick, Jr. all returned as judges for the show's fourteenth and fifteenth seasons.
Document 5: American Idol: The fourteenth season premiered on January 7, 2015. Ryan Seacrest returned to host, while Jennifer Lopez, Keith Urban and Harry Connick, Jr. returned for their respective fourth, third and second seasons as judges. Eighth season runner-up Adam Lambert filled in for Urban during the New York City auditions. Randy Jackson did not return as the in-house mentor for this season.
Document 6: American Idol: Beginning in the tenth season[citation needed], permanent mentors were brought in during the live shows to help guide the contestants with their song choice and performance. Jimmy Iovine was the mentor in the tenth through twelfth seasons, former judge Randy Jackson was the mentor for the thirteenth season and Scott Borchetta was the mentor for the fourteenth and fifteenth season. The mentors regularly bring in guest mentors to aid them, including Akon, Alicia Keys, Lady Gaga, and current judge Harry Connick, Jr..
Document 7: American Idol: With the exception of seasons one and two, the contestants in the semifinals onwards perform in front of a studio audience. They perform with a full band in the finals. From season four to season nine, the American Idol band was led by Rickey Minor; from season ten onwards, Ray Chew. Assistance may also be given by vocal coaches and song arrangers, such as Michael Orland and Debra Byrd to contestants behind the scene. Starting with season seven, contestants may perform with a musical instrument from the Hollywood rounds onwards. In the first nine seasons, performances were usually aired live on Tuesday nights, followed by the results shows on Wednesdays in the United States and Canada, but moved to Wednesdays and Thursdays in season ten.
Document 8: Say You, Say Me: "Say You, Say Me" is a song written and recorded by Lionel Richie for the film "White Nights", starring Mikhail Baryshnikov and Gregory Hines. The single hit number 1 in the US and on the R&B singles chart in December 1985. It became Richie's ninth number one on the "Billboard" Adult Contemporary chart. The track is not available on the soundtrack album to the film, because Motown did not want Richie's first single since the "Can't Slow Down" album to appear on another record label. It finally appeared on the "Dancing on the Ceiling" album released in 1986.
Document 9: Stuck on You (Lionel Richie song): "Stuck on You" is a song written by and originally recorded by Lionel Richie. It was the fourth single released from his second studio album "Can't Slow Down" released on May 1, 1984, by Motown, and achieved chart success, particularly in the U.S. and the UK, where it peaked at number three and number 12, respectively. The song differs from Richie's other compositions, as it displays a country pop influence rather than R&B. As such, the single's cover photo shows Richie wearing a cowboy hat, and indeed, "Stuck on You" peaked at number 24 on the country chart. "Stuck on You" reached number one on the Adult Contemporary chart, Richie's seventh chart topper. The song marks Lionel Richie's country music debut.
Document 10: American Idol: American Idol employs a panel of judges who critique the contestants' performances. The original judges were record producer and music manager Randy Jackson, pop singer and choreographer Paula Abdul and music executive and manager Simon Cowell. The judging panel for the most recent season consisted of country singer Keith Urban, singer and actress Jennifer Lopez, and jazz singer Harry Connick, Jr. The show was originally hosted by radio personality Ryan Seacrest and comedian Brian Dunkleman, with Seacrest continuing on for the rest of the seasons.
Document 11: American Idol: The show had originally planned on having four judges following the Pop Idol format; however, only three judges had been found by the time of the audition round in the first season, namely Randy Jackson, Paula Abdul and Simon Cowell. A fourth judge, radio DJ Stryker, was originally chosen but he dropped out citing "image concerns". In the second season, New York radio personality Angie Martinez had been hired as a fourth judge but withdrew only after a few days of auditions due to not being comfortable with giving out criticism. The show decided to continue with the three judges format until season eight. All three original judges stayed on the judging panel for eight seasons.
Document 12: American Idol: Guest judges may occasionally be introduced. In season two, guest judges such as Lionel Richie and Robin Gibb were used, and in season three Donna Summer, Quentin Tarantino and some of the mentors also joined as judges to critique the performances in the final rounds. Guest judges were used in the audition rounds for seasons four, six, nine, and fourteen such as Gene Simmons and LL Cool J in season four, Jewel and Olivia Newton-John in season six, Shania Twain in season eight, Neil Patrick Harris, Avril Lavigne and Katy Perry in season nine, and season eight runner-up, Adam Lambert, in season fourteen.
Document 13: Ballerina Girl: "Ballerina Girl" is a 1986 song written and recorded by Lionel Richie. The song is a track from Richie's "Dancing on the Ceiling" album. "Ballerina Girl" peaked at number five on the soul charts. The song was also the last of Richie's eleven number ones on the Adult Contemporary charts. "Ballerina Girl" spent four weeks at number one and went to number seven on the "Billboard" Hot 100 in early 1987.
Document 14: All Night Long (All Night): ``All Night Long (All Night) ''7'' cover Single by Lionel Richie from the album Ca n't Slow Down B - side`` Wandering Stranger ''Released August 31, 1983 Format 7 ``, 12'' Length 4: 20 (Single edit) 6: 19 (Album version) Label Motown Songwriter (s) Lionel Richie Producer (s) Lionel Richie James Anthony Carmichael Lionel Richie singles chronology`` My Love ''(1983) ``All Night Long (All Night)'' (1983)`` Running with the Night ''(1983) ``My Love'' (1983)`` All Night Long (All Night) ''(1983) ``Running with the Night'' (1983)
Document 15: My Love (Lionel Richie song): "My Love" is the title of a 1983 hit song by the American singer-songwriter Lionel Richie. It was the third single released off Richie's self-titled debut solo album. The song features harmony backing vocals by country music singer Kenny Rogers. It reached the Top 10 on three notable "Billboard" magazine charts in the spring of 1983: on the pop chart, the song peaked at # 5; on the adult contemporary chart, the song spent four weeks at # 1; and on the R&B chart, the song topped out at # 6. "My Love" was not among Richie's more successful singles in the United Kingdom, where it only managed # 70 on the UK Singles Chart. In Canada in peaked on the RPM Singles chart at #28.
ground_truth: season two
sub_queries: The song or album Ballerina Girl came from which artiste? Answer: Lionel Richie
In what season was Lionel Richie a guest judge on American Idol? Answer: season two