Question: How old was the singer who joined Madonna on MTV unplugged when she started Hannah Montana?

full_context: Document 1: Who Said: "Who Said" is a pop song by American recording artist and actress Miley Cyrus. She is performing as Hannah Montana – the alter ego of Miley Stewart, a character she plays on the Disney Channel television series "Hannah Montana". The song was written by Matthew Gerrard, Robbie Nevil, and Jay Landers and produced by Gerrard. It was released on July 11, 2006 by Walt Disney Records as a promotional single from the series' first soundtrack, "Hannah Montana". "Who Said" bears teen pop aspects musically, while its lyrics are about individualism.
Document 2: Beyoncé: In December, Beyoncé along with a variety of other celebrities teamed up and produced a video campaign for "Demand A Plan", a bipartisan effort by a group of 950 US mayors and others designed to influence the federal government into rethinking its gun control laws, following the Sandy Hook Elementary School shooting. Beyoncé became an ambassador for the 2012 World Humanitarian Day campaign donating her song "I Was Here" and its music video, shot in the UN, to the campaign. In 2013, it was announced that Beyoncé would work with Salma Hayek and Frida Giannini on a Gucci "Chime for Change" campaign that aims to spread female empowerment. The campaign, which aired on February 28, was set to her new music. A concert for the cause took place on June 1, 2013 in London and included other acts like Ellie Goulding, Florence and the Machine, and Rita Ora. In advance of the concert, she appeared in a campaign video released on 15 May 2013, where she, along with Cameron Diaz, John Legend and Kylie Minogue, described inspiration from their mothers, while a number of other artists celebrated personal inspiration from other women, leading to a call for submission of photos of women of viewers' inspiration from which a selection was shown at the concert. Beyoncé said about her mother Tina Knowles that her gift was "finding the best qualities in every human being." With help of the crowdfunding platform Catapult, visitors of the concert could choose between several projects promoting education of women and girls. Beyoncé is also taking part in "Miss a Meal", a food-donation campaign, and supporting Goodwill charity through online charity auctions at Charitybuzz that support job creation throughout Europe and the U.S.
Document 3: Miley Cyrus: Cyrus auditioned for the Disney Channel television series Hannah Montana when she was eleven years old. She auditioned for the role of the title character's best friend, but was called to audition for the lead role instead. Despite being denied the part at first because she was too ``young and small ''for the role, she was selected later as the lead because of her singing and acting abilities. The series premiered in March 2006 to the largest audience for a Disney Channel program, and quickly ranked among the highest - rated series on basic cable. The instant success of the series led to Cyrus being labeled a`` teen idol''. She toured with The Cheetah Girls as Hannah Montana in September 2006, performing songs from the show's first season. Walt Disney Records released a soundtrack credited to Cyrus' character in October of that year. The record was a commercial success, topping the Billboard 200 chart in the United States; it went on to sell over three million copies worldwide. With the release of the soundtrack, Cyrus became the first act within The Walt Disney Company to have deals in television, film, consumer products, and music. She had a two - year relationship with actor Tyler Posey. Cyrus has stated that she dated singer and actor Nick Jonas from June 2006 to December 2007, claiming they were ``in love ''and began dating soon after they first met. Her relationship with Jonas, as well as her`` spoofing'' fellow Disney alums Selena Gomez and Demi Lovato, attracted considerable media attention. Cyrus came out as pansexual to her mother when she was 14, and has said: ``I never want to label myself! I am ready to love anyone that loves me for who I am! I am open. ''
Document 4: Madonna (entertainer): By 2013, Madonna's Raising Malawi organization built ten schools to educate 4,000 children in Malawi at a value of $400,000. When Madonna visited the schools in April 2013, President of Malawi Joyce Banda expressed criticism of the star and her charity, accusing her of exaggerating her charity's contribution. Madonna responded by releasing a statement saying she was saddened that Banda had chosen to act negatively about her endeavors. "I have no intention of being distracted by these ridiculous allegations," she added. Later, it was confirmed that Banda had not approved the statement released written by her press team and was "incandescent with anger" over the mix-up.
Document 5: 7 Things: "7 Things" is a song by American singer Miley Cyrus. The song was co-written by Cyrus, Antonina Armato and Tim James, and produced by John Fields. It was released on June 17, 2008 by Hollywood Records as the lead single from the first studio album released by Cyrus with no ties to her character Hannah Montana from the Disney Channel comedy series of the same name. Also registered as "Seven Things I Hate About You", Cyrus developed the song during the Best of Both Worlds Tour while feeling numerous emotions for an ex-boyfriend, mainly anger. The song's release brought allegations that it was about Nick Jonas of the Jonas Brothers, which Cyrus neither confirmed nor denied. Musically, "7 Things" bears aspects of both country and pop punk, while the lyrics in the song's refrain list seven traits Cyrus hates about an ex-boyfriend.
Document 6: Madonna (entertainer): Madonna released and performed the song "Hey You" at the London Live Earth concert in July 2007. She announced her departure from Warner Bros. Records, and declared a new $120 million, ten-year 360 deal with Live Nation. In 2008, Madonna produced and wrote I Am Because We Are, a documentary on the problems faced by Malawians; it was directed by Nathan Rissman, who worked as Madonna's gardener. She also directed her first film, Filth and Wisdom. The plot of the film revolved around three friends and their aspirations. The Times said she had "done herself proud" while The Daily Telegraph described the film as "not an entirely unpromising first effort [but] Madonna would do well to hang on to her day job." On March 10, 2008, Madonna was inducted into the Rock and Roll Hall of Fame in her first year of eligibility. She did not sing at the ceremony but asked fellow Hall of Fame inductees and Michigan natives The Stooges to perform her songs "Burning Up" and "Ray of Light".Madonna released her eleventh studio album, Hard Candy, in April 2008. Containing R&B and urban pop influences, the songs on Hard Candy were autobiographical in nature and saw Madonna collaborating with Justin Timberlake, Timbaland, Pharrell Williams and Nate "Danja" Hills. The album debuted at number one in 37 countries and on the Billboard 200. Caryn Ganz from Rolling Stone complimented it as an "impressive taste of her upcoming tour", while BBC correspondent Mark Savage panned it as "an attempt to harness the urban market".
Document 7: Madonna (entertainer): Madonna released the song "Hey You" for the Live Earth series of concerts. The song was available as a free download during its first week of release. She also performed it at the London Live Earth concert. Madonna announced her departure from Warner Bros. Records, and a new $120 million, ten-year 360 deal with Live Nation. She produced and wrote I Am Because We Are, a documentary on the problems faced by Malawians. The documentary was directed by Nathan Rissman, who worked as Madonna's gardener. She also directed her first film Filth and Wisdom. The plot of the film revolved around three friends and their aspirations. The Times said she had "done herself proud" while The Daily Telegraph described the film as "not an entirely unpromising first effort [but] Madonna would do well to hang on to her day job." In December 2007, the Rock and Roll Hall of Fame announced Madonna as one of the five inductees of 2008. At the induction ceremony on March 10, 2008, Madonna did not sing but asked fellow Hall of Fame inductees and Michigan natives The Stooges to perform her songs "Burning Up" and "Ray of Light". She thanked Christopher Flynn, her dance teacher from 35 years earlier, for his encouragement to follow her dreams.
Document 8: Gonna Get This: "Gonna Get This" is a pop song by American singer-songwriter and actress Miley Cyrus, performing as Hannah Montana – the alter ego of Miley Stewart – a character she plays on the Disney Channel television series "Hannah Montana". It also features vocals from R&B singer Iyaz. It was released to Radio Disney on September 24, 2010 as promotion for the fourth season of "Hannah Montana". The song is musically dance-pop based. The song was later released on October 5, 2010 through iTunes as a single from the soundtrack of the same title as the special title ("Hannah Montana Forever") of the fourth and final season of the series.
Document 9: Madonna (entertainer): Madonna gave another provocative performance later that year at the 2003 MTV Video Music Awards, while singing "Hollywood" with Britney Spears, Christina Aguilera, and Missy Elliott. Madonna sparked controversy for kissing Spears and Aguilera suggestively during the performance. In October 2003, Madonna provided guest vocals on Spears' single "Me Against the Music". It was followed with the release of Remixed & Revisited. The EP contained remixed versions of songs from American Life and included "Your Honesty", a previously unreleased track from the Bedtime Stories recording sessions. Madonna also signed a contract with Callaway Arts & Entertainment to be the author of five children's books. The first of these books, titled The English Roses, was published in September 2003. The story was about four English schoolgirls and their envy and jealousy of each other. Kate Kellway from The Guardian commented, "[Madonna] is an actress playing at what she can never be—a JK Rowling, an English rose." The book debuted at the top of The New York Times Best Seller list and became the fastest-selling children's picture book of all time.
Document 10: Hannah Montana (soundtrack): Hannah Montana is the soundtrack album for the first season of the television series "Hannah Montana", released on October 24, 2006 by Walt Disney Records. The program itself premiered through the Disney Channel on March 24, 2006; after becoming an immediate commercial success, production on its soundtrack began the following month. Eight of its thirteen tracks are performed by the series' primary actress Miley Cyrus, and are credited to her character Hannah Montana. The groups The Click Five, Everlife, B5, and recording artist Jesse McCartney each contribute one recording, while a duet between Cyrus and her father Billy Ray Cyrus is included as the final track. "Hannah Montana" was reissued as a two-disc special edition on March 20, 2007. The soundtrack was further promoted during the Cheetah Girls' Party's Just Begun Tour, for which Cyrus served as an opening act, and her own Best of Both Worlds Tour.The soundtrack is primarily a teen pop record, which sees additional influences from pop rock and country pop musical styles. The lyrical themes revolve largely around "girl power", teen romance, and the double life that Cyrus' character lives on the program.
Document 11: Madonna (entertainer): From the beginning of 2014, Madonna began to make multiple media appearances. She appeared at the 56th Annual Grammy Awards in January 2014, performing "Open Your Heart" alongside rappers Macklemore & Ryan Lewis and singer Mary Lambert, who sang their single "Same Love", as 33 couples were wed onstage, officiated by Queen Latifah. Days later, she joined singer Miley Cyrus on her MTV Unplugged special, singing a mash-up of "Don't Tell Me" and Cyrus' single "We Can't Stop" (2013). She also extended her business ventures and in February 2014 the singer premiered MDNA Skin, a range of skin care products, in Tokyo, Japan. After visiting her hometown of Detroit during May 2014, Madonna decided to contribute funds to three of the city's organizations, to help eliminate poverty from there. The singer released a statement saying that she was inspired by their work, adding that "it was obvious to me that I had to get involved and be part of the solution to help Detroit recover".
Document 12: Breakout (Miley Cyrus album): Breakout is the second studio album by American recording artist Miley Cyrus, released on July 22, 2008 by Hollywood Records. It is her first record that is not affiliated with the television series "Hannah Montana", in which Cyrus portrays the title character Hannah Montana. She co-wrote eight of its thirteen tracks, several of which with the assistance of Antonina Armato and Tim James. The majority of the record was composed as she traveled during her headlining Best of Both Worlds Tour (2007–08). Overall, "Breakout" is dominant on pop rock but explores a variety of other musical genres. Lyrical themes addressed in the album relate to breakups and coming of age. An international version was reissued on September 1, 2008.
Document 13: Hannah Montana (season 1): The first season of the television series Hannah Montana was aired on Disney Channel from March 24, 2006 to March 30, 2007, and included 26 episodes. It introduces the five main characters of the series and Miley Stewart's situation of living a secret double life as a teen pop star. The season also introduces several significant recurring characters such as Roxy Roker, Jake Ryan, and Rico Suave.
Document 14: Madonna (entertainer): Madonna also began work on her thirteenth studio album, with collaborators including Avicii, Diplo and Natalia Kills. In December 2014, thirteen demos recorded for the album leaked onto the Internet. She posted in response that half of the tracks would not be used on the final release, while the other half had "changed and evolved". The album, titled Rebel Heart, was released on March 10, 2015. From September 2015, she embarked on the Rebel Heart Tour to promote the album; the tour ended in March 2016 and traveled throughout North America, Europe and Asia and was the singer's first visit to Australia in 23 years, where she also performed a one-off show for her fans. It grossed a total of $169.8 million from the 82 shows, with over 1.045 million ticket sales. While on tour Madonna became embroiled in a legal battle with Ritchie, over the custody of her son Rocco. The dispute started when Rocco decided to continue living at England with Ritchie when the Rebel Heart Tour had visited there, while Madonna wanted him to return with her. Court hearings took place in both New York and London, and after multiple deliberations, Madonna decided to withdraw her application for custody, and appealed for a mutual discussion between herself and Ritchie about Rocco.
Document 15: Hannah Montana (season 2): ``I Want You to Want Me... to Go to Florida ''features the ballad`` Ready, Set, Do n't Go'' by Billy Ray Cyrus. It details his feelings concerning his daughter Miley's move to Los Angeles to star in Hannah Montana, while he stayed behind in Nashville. The episode also features the song ``If Cupid Had a Heart '', by Julie Griffin, and written by Gordon Pogoda. Mikayla (Selena Gomez), lip - syncs it in the episode. A soundtrack for the season featuring 10 songs sung by Miley Cyrus as Hannah Montana was released on June 26, 2007.
ground_truth: eleven years old
sub_queries: Which singer did she join on MTV Unplugged to sing? Answer: Miley Cyrus
what age did Miley Cyrus start hannah montana Answer: eleven years old