Barbadian recording artist Rihanna has embarked on four concert tours, three of which have been worldwide.
 Her 2006 debut, was based in North America only and supported her first and second studio album, "Music of the Sun" (2005) and "A Girl like Me" (2006).
 The tour lasted for three months, through which Rihanna performed 36 shows.
 The same year, Rihanna continued to tour as a special guest on the PCD World Tour with Pussycat Dolls, Roc the Block Tour with Jay-Z and Ne-Yo, and the Monkey Business Tour with Black Eyed Peas.
 In the period from 2007 till 2009, she performed on the worldwide Good Girl Gone Bad Tour in a support of her third studio album with same name.
 During the tour, Rihanna visited Europe, North America, Oceania, Asia and Africa.
 It featured Rihanna presenting completely different style and wearing leather outfits.
 The Good Girl Gone Bad Tour sparked controversy in Malaysia where the Pan-Malaysian Islamic Party recommended that Rihanna's concert tour should be banned due her provocative outfits.
 A DVD, titled "Good Girl Gone Bad Live" was released on June 16, 2008.
 It features the show from Evening News Arena in Manchester, England, held on December 6, 2007.
"Break It Off" is a song by Barbadian singer Rihanna from her second studio album "A Girl like Me" (2006), and features guest vocals from Sean Paul.
 It was written by Donovan Bennett, Paul, K. Ford and Rihanna, while production was handled by Don Corleon.
 The song was released on November 13, 2006, as the album's fourth and final single.
 "Break It Off" is a futuristic pop-dancehall song, which is layered over an electro-reggae beat.
A Girl like Me is the second studio album by Barbadian singer Rihanna.
 It was released on April 10, 2006 by Def Jam Recordings.
 For the production of the album, Rihanna worked with Evan Rogers, Carl Sturken, StarGate, J. R. Rotem and label-mate Ne-Yo, who wrote the album's second single.
 "A Girl like Me" is a pop, reggae and R&B album influenced by Rihanna's Caribbean roots.
 The album also incorporates elements of dancehall and rock, as well as ballads, which music critics were ambivalent towards.
"Unfaithful" is a song by Barbadian singer Rihanna from her second studio album "A Girl like Me" (2006).
 It was written by Shaffer "Ne-Yo" Smith with the song's producers StarGate.
 The song was released by Def Jam Recordings on May 2, 2006, as the second single from the album.
 "Unfaithful" is a pop and R&B ballad and was inspired by the works of American rock band Evanescence.
 Originally titled "Murderer", the single speaks about a woman who regrets cheating on her partner.
"SOS" is a song by Barbadian singer Rihanna from her second studio album "A Girl like Me" (2006).
 It was written by Jonathan "J.R." Rotem, E. Kidd Bogart and Ed Cobb, with production was handled by Rotem, Carl Sturken and Evan Rogers.
 It was released on February 14, 2006, as the lead single from the album.
 "SOS" is a dance-pop song which samples Soft Cell's 1981 recording of "Tainted Love", a song written by Cobb in 1965.
 Critical reception of "SOS" was generally positive, with the majority of music critics praising the inclusion of the "Tainted Love" sample.
 Some critics compared "SOS" to Rihanna's debut single, "Pon de Replay" ("Music of the Sun", 2005).
Good Girl Gone Bad Live is the first live long-form video by Barbadian singer Rihanna.
 It was first released on June 9, 2008 by Def Jam Recordings.
 The DVD and Blu-ray release features Rihanna's concert at the Manchester Arena in Manchester, United Kingdom held on December 6, 2007, as part of her Good Girl Gone Bad Tour (2007—2009) which supported singer's third studio album "Good Girl Gone Bad" (2007).
 Most of the concert's set list originates from "Good Girl Gone Bad", however, Rihanna also performed songs from her previous albums "Music of the Sun" (2005) and "A Girl like Me" (2006).
 It also contains a special Documentary Feature that presents Rihanna discussing her experiences during the tour.
Barbadian singer Rihanna has recorded material for her eight studio albums and has collaborated with other artists for duets and featured songs on their respective albums and charity singles.
 After signing a record contract with the Def Jam Recordings in February 2005, Rihanna began to work with producers Carl Sturken and Evan Rogers, who co-wrote and co-produced 12 out of the 15 songs on her 2005 debut album, "Music of the Sun".
 Award-winning songwriter Diane Warren co-wrote the title track, while Grammy Award-winning singer-songwriter Deniece Williams co-wrote the song "Willing to Wait".
 Sturken and Rogers co-wrote and co-produced 9 songs out of 16 on Rihanna's 2006 album "A Girl like Me".
 The album's lead single "SOS" was written by Evan "Kidd" Bogart and J. R. Rotem.
 It contains a sped-up sample of "Tainted Love", written in 1965 by Ed Cobb, who was credited as a co-writer on "SOS".
Barbadian singer Rihanna has released four video albums and appeared in fifty-two music videos, six films, ten television programs, and eight television commercials.
 In 2005, Rihanna signed a recording contract with Def Jam Recordings and released her debut single "Pon de Replay", taken from her first studio album "Music of the Sun" (2005).
 Like its lyrical theme, the music video for the song was inspired by disco and dance; it was directed by Little X.
 Three separate videos were released for "SOS", the lead single from her second studio album "A Girl Like Me" (2006), all of which contained various dance sequences.
 The same year, American director Anthony Mandler directed the accompanying music video for the second single "Unfaithful", which featured Rihanna in a dangerous love triangle with her lover and her husband.
 "Unfaithful" was Rihanna's first collaboration with Mandler; they later worked together regularly.
 Also in 2006, Rihanna played herself in the third installment of the "Bring It On" film series, entitled "".
Good Girl Gone Bad is the third studio album by Barbadian singer Rihanna.
 It was released on May 31, 2007, by Def Jam Recordings and SRP Records.
 Rihanna worked with various producers on the album, including Christopher "Tricky" Stewart, Terius "Dream" Nash, Neo da Matrix, Timbaland, Carl Sturken, Evan Rogers and StarGate.
 Inspired by Brandy Norwood's fourth studio album "Afrodisiac" (2004), "Good Girl Gone Bad" is a pop, dance-pop and R&B album with 1980s music influences.
 Described as a turning point in Rihanna's career, it represents a departure from the Caribbean sound of her previous releases, "Music of the Sun" (2005) and "A Girl like Me" (2006).
 Apart from the sound, she also endorsed a new image for the release going from an innocent girl to an edgier and more sexual look.
"Do You" is a 2007 single by American singer-songwriter Ne-Yo.
 It is about Ne-Yo questioning his ex-girlfriend if she ever thinks about him anymore.
 It is the second single from his second album, "Because of You".
 The single was officially released to radio the week of June 12, 2007.
 In an interview with BET, Ne-Yo said that "Do You" is the second part to his song "So Sick" from his debut album, "In My Own Words".

Question: What was Rihanna's second single from her 2006 album "A Girl Like Me," written by Ne-Yo?
Answer: Unfaithful