Question: Who sings the rap portion in Baby, by the performer of My Worlds Acoustic?

full_context: Document 1: Somebody to Love (Justin Bieber song): "Somebody to Love" is a song performed by Canadian recording artist Justin Bieber. The song served as the second single from his album, "My World 2.0". It was written by Heather Bright and The Stereotypes, and produced by the latter. The song was originally recorded as a demo by Bieber's mentor, R&B singer, Usher, for his sixth studio album, "Raymond v. Raymond" (2010). After things went stale with Usher's label, The Stereotypes were encouraged to give the song to Bieber, who recorded it, with Usher performing background vocals. The song is an upbeat pop song, which also derives from R&B genre, while making use of Eurodisco influences. It impacted US mainstream and rhythmic radio on April 20, 2010. The remix of the song featuring Usher was featured on Bieber's first compilation album "" and his second remix album "".
Document 2: Change Me (Justin Bieber song): "Change Me" is a song by Canadian recording artist Justin Bieber from his second compilation album "Journals" (2013) discussing his life after the world turned on him was released on December 2, 2013. The song is the ninth in Bieber's series Music Mondays, the first eight being "Heartbreaker" (October 7, 2013), "All That Matters" (October 14), "Hold Tight" (October 21), "Recovery" (October 28), "Bad Day" (November 4), "All Bad" (November 11), "PYD" (November 18) and "Roller Coaster" (November 25). Bieber released a new single every week for 10 weeks from October 7 to December 9, 2013.
Document 3: Love Yourself: ``Love Yourself ''is a song recorded by Canadian singer Justin Bieber for his fourth studio album Purpose (2015). The song was released first as a promotional single on November 8, 2015, and later was released as the album's third single. It was written by Ed Sheeran, Benny Blanco and Bieber, and produced by Blanco. An acoustic pop song,`` Love Yourself'' features an electric guitar and a brief flurry of trumpets as its main instrumentation. During the song, Bieber uses a husky tone in the lower registers. Lyrically, the song is a kiss - off to a narcissistic ex-lover who did the protagonist wrong.
Document 4: Baby Boy (Beyoncé song): "Baby Boy" is a song by American singer Beyoncé featuring Jamaican dancehall singer Sean Paul from Beyoncé's debut solo studio album "Dangerously in Love" (2003). Both artists co-wrote the song with Scott Storch, Robert Waller and Shawn "Jay-Z" Carter; the former also co-produced the song. Containing a lyrical interpolation of "No Fear" by hip hop group O.G.C, "Baby Boy" is an R&B and dancehall song with reggae and Arabic music influences; its lyrics detail a woman's fantasies.
Document 5: Justin Bieber: Justin Drew Bieber (/ ˈbiːbər /; born March 1, 1994) is a Canadian singer and songwriter. After a talent manager discovered him through his YouTube videos covering songs in 2008 and signed to RBMG, Bieber released his debut EP, My World, in late 2009. It was certified Platinum in the U.S. He became the first artist to have seven songs from a debut record chart on the Billboard Hot 100. Bieber released his first full - length studio album, My World 2.0, in 2010. It debuted at or near number one in several countries, was certified triple Platinum in the U.S., and contained his single ``Baby ''.
Document 6: My Worlds Acoustic: My Worlds Acoustic is the first remix album by Canadian recording artist Justin Bieber. It was released on November 26, 2010 and was initially sold exclusively at Walmart retail stores and Sam's Club. The album features nine acoustic versions of songs from his debut extended play, "My World" (2009), and first album "My World 2.0" (2010), as well as a new song "Pray". The new versions of the songs were produced by Bieber's music director, Dan Kanter, his vocal producer Kuk Harrell, and also producer Rob Wells. Internationally, the set is included as a part of the compilation album, "" (2010), which included songs from the previous two releases. "My Worlds Acoustic" was released to iTunes, on February 8, 2011.
Document 7: Journals (album): On December 9, 2013, Bieber announced that the ten Music Monday releases would be packaged with an additional five new songs in a compilation entitled Complete My Journals. Although the album was initially set for release on December 16, 2013, the date was pushed back one week to December 23, as Bieber intended to include one more song on the compilation. Though it does not appear on the album itself, the bonus track, ``Flatline '', was available for a free download on the iTunes Store for a limited time. Journals was available on iTunes from January 2, 2014, and all sixteen songs are available for purchase individually. According to one of its producers and Bieber's personal friend, Jason`` Poo Bear'' Boyd, the album was supposed to receive a full release, as well as its singles to be promoted on radio, however the label did n't support it because it was n't the direction they wanted Justin to go. It was, however, eventually released on LP in 2016.
Document 8: When I Was Your Man: ``When I Was Your Man ''was written by Andrew Wyatt, Bruno Mars, Philip Lawrence and Ari Levine, while production was handled by the latter three production - team The Smeezingtons. Having chord progressions Am - C - Dm - G - G7 - C (verse) and F-G-C (chorus), the song is written in the key of C Major, with Mars' vocals range from the low note of G3 to the high note of C5. The pop piano ballad finds Mars singing about a pre-fame heartbreak as he regrets letting his woman get away. It starts with a rolling piano riff; unto a nearly scat`` vocal cadence'': ``Same bed but it feels just a little bit bigger now / Our song on the radio but it do n't sound the same '', as he laments the`` single state'' he created for himself. Next, he sings of his failings; to do right by his woman, ``I shoulda bought you flowers / And held your hand / Shoulda gave you all my hours / When I had the chance ''. Its title phrase re-emerges in the final chorus, juxtaposed by Bruno from all the things he`` shoulda'' done, into things he hopes his ex's new man will do; concluding: ``Do all of the things I should have done / When I was your man ''. In an interview to Rolling Stone, Mars revealed, while reluctant, that he wrote the song for his girlfriend, model Jessica Caban, when he was worried about losing her. In contrast with the song, Mars and Caban stayed together; remaining a couple as of 2014. Mars also said, in the interview, that he finds it difficult to perform the song; saying:`` You're bringing up all these old emotions again,'' and that: ``It's just like bleeding! ''
Document 9: Down to Earth (Justin Bieber song): "Down to Earth" is a song by Canadian recording artist Justin Bieber, included as a track on his debut release, "My World", released on November 17, 2009. It was written by Bieber, who was assisted by Carlos and Steven Battey of The Jackie Boyz, as well as the song's producers, Mason "MdL" Levy, and Kevin Risto and Waynne Nugent of Midi Mafia. "Down to Earth" is a teen pop song, with lyrics that were inspired by the divorce of Bieber's parents. It also contains lyrical content about growing up. The song received positive reviews from critics, who embraced the song as a shift in the puppy love content of the album. After the release of My World, due to digital sales, the song charted in the lower regions of charts in the United States, Canada, and the United Kingdom.
Document 10: All Around the World (Justin Bieber song): "All Around the World" is a song by Canadian singer Justin Bieber, from his third studio album, "Believe" (2012). It was written by Bieber, Sir Nolan and Nasri of The Messengers in collaboration with Ludacris, who guest features. This was the second collaboration between Bieber and Ludacris, having previously collaborated on "Baby" (2010). It was first released on June 4, 2012, as a promotional single from the album. The song was released as the fourth international single, and the fifth and final US single on February 26, 2013. The Eurodance track features a similar instrumentation to songs by Britney Spears, Chris Brown and Usher. Lyrically, it features Bieber singing to his love interest that "all around the world, people want to be loved". "All Around the World" received mostly positive reviews from music critics, who welcomed the song's Eurodance style. The song had moderate success worldwide, reaching the top ten in several countries, such as Belgium, Canada and Norway. Bieber promoted the song through live performances and a music video.
Document 11: Baby (Justin Bieber song): The song is predominantly upbeat, featuring Bieber's R&B vocals over a backdrop containing a dance infused beat, full of keyboard and ``disco string ''synths. The song is composed in the key of E ♭ major with Bieber's vocal range spanning from the low - note of G to the high - note of C. According to Jody Rosen of Rolling Stone, the song`` blends winks at Fifties doo - wop with hip - hop chants'', comparing the style and the lyrics ``My first love broke my heart for the first time / And I was like / Baby, baby, baby, ooooh / I thought you'd always be mine ''to fifties ballads like`` Tears on My Pillow'', ``Why Do Fools Fall in Love ''and`` Earth Angel''. Lyrically, Bieber's lines explain his distress over his lost love, and promise to get it back, featured in lines like, ``And I wan na play it cool / But I'm losin 'you... / I'm in pieces / So come and fix me... ''. The chorus features the distinct and repetitive`` baby, baby, baby, ohhhh (nooooo)'' hook. After the second verse, Ludacris comes in with the verse - rap, an anecdote of young love when he was thirteen, as it runs ``When I was 13 / I had my first love / She had me going crazy / Oh, I was star - struck / She woke me up daily / Do n't need no Starbucks... ''.
Document 12: Acoustic (John Lennon album): Acoustic is a compilation album of John Lennon demos, studio and live performances that feature his acoustic guitar work and was released in 2004.
Document 13: Love Yourself: Lyrically, ``Love Yourself ''is a kiss - off to a narcissistic ex-lover who did the protagonist wrong, with Bieber singing in a snappy and spiteful tone while`` hating on a girl for loving herself too much.'' In the pre-chorus, he sings with a husky tone in the lower registers: ``My mama do n't like you, and she likes everyone, ''`` in a style that molds well to Sheeran's,'' according to Rolling Stone's Brittany Spanos. ``And I (never) like to admit that I was wrong. And I've been so caught up in my job, did n't see what's going on, and now I know, I'm better sleeping on my own, ''he continues. In the chorus, Bieber sings,`` Cause if you like the way you look that much, oh baby you should go and love yourself,'' which according to Digital Spy's Amy Davidson, ``'love yourself' means' go f * * k yourself 'in this context. ''On March 7, 2017, composer Ed Sheeran stated on the Howard Stern Show that he had Rihanna in mind for the song at first, and the original lyric was indeed`` fuck yourself.'' In the song's bridge, Bieber uses a ``brass - and - vocalese ''style.
Document 14: Baby (Justin Bieber song): Filming for the music video began during the week of January 25, 2010, in Los Angeles. It was filmed at Universal CityWalk by director Ray Kay, who had previously directed videos for Beyoncé Knowles, Lady Gaga, Alexandra Burke, and Cheryl Cole, among others. Ludacris said that the video ``is like a 2010 version of Michael Jackson's`` The Way You Make Me Feel ''.'' Bieber said that the video ``will capture the song's message of trying to woo back a girl. ''In explaining the concept of the video, Bieber said,`` It starts off, I really like this girl, but we did n't (get) along; we could n't be together. Basically I want her back and (I'm) kind of going through the whole thing. I'm chasing her around, trying to get her, and she's kind of playing hard to get, but I'm persistent. I keep going.'' The video premiered exclusively on Vevo on Friday, February 19, 2010. Singer and actress Jasmine Villegas portrays Bieber's love interest in the video. Bieber's friends, Young Money artists Drake and Lil Twist also appeared in the video, along with Tinashe and jerkin 'crew The Rangers.
Document 15: Justin Bieber: Justin Drew Bieber (/ ˈbiːbər /; born March 1, 1994) is a Canadian singer, actor and songwriter. After a talent manager discovered him through his YouTube videos covering songs in 2008 and he signed to RBMG, Bieber released his debut EP, My World, in late 2009. It was certified platinum in the U.S. He became the first artist to have seven songs from a debut record chart on the Billboard Hot 100. Bieber released his first full - length studio album, My World 2.0, in 2010. It debuted at or near number one in several countries, was certified triple platinum in the U.S., and contained his single ``Baby ''.
ground_truth: Ludacris
sub_queries: My Worlds Acoustic >> performer Answer: Justin Bieber
who sings the rap in baby by Justin Bieber Answer: Ludacris