Question: What song was written for Justin Bieber by the artist who sings Everything Has Changed with Taylor Swift?

full_context: Document 1: Everything Has Changed: ``Everything Has Changed ''is a song written and performed by American singer - songwriter Taylor Swift and English singer - songwriter Ed Sheeran, taken from Swift's fourth studio album, Red (2012). Produced by Butch Walker, the track was released as the sixth single from the album on July 16, 2013.`` Everything Has Changed'' is a guitar ballad combining folk and pop genres about ``wanting to get to know a new lover better ''.
Document 2: Love Yourself: Tear: Love Yourself 轉 'Tear' (stylized as LOVE YOURSELF 轉 'Tear') is the third Korean studio album (sixth overall) by South Korean boy band BTS. The album was released on May 18, 2018 by Big Hit Entertainment. It is available in four versions and contains eleven tracks, with ``Fake Love ''as its lead single. The concept album explores themes relating to the pains and sorrows of separation. It debuted at number one on the US Billboard 200, becoming BTS 'highest - charting album in a Western market, as well as the first K - pop album to top the US albums chart and the highest - charting album by an Asian act.
Document 3: 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 4: Love Yourself: Tear: Love Yourself 轉 'Tear' (stylized as LOVE YOURSELF 轉 'Tear') is the third Korean studio album (sixth overall) by South Korean boy band BTS. The album was released on May 18, 2018 by Big Hit Entertainment. It is available in four versions and contains eleven tracks, with ``Fake Love ''as its lead single. The concept album explores themes relating to the pains and sorrows of separation. On May 27, 2018, the album debuted at number one on the US Billboard 200, earning 135,000 album - equivalent units becoming BTS 'highest - charting album in a Western market, as well as the first K - pop album to top the US albums chart and the highest - charting album by an Asian act.
Document 5: 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 6: 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 7: What Do You Mean?: ``What Do You Mean? ''is a song recorded by Canadian singer Justin Bieber for his fourth studio album Purpose (2015). The song was released on August 28, 2015, as the album's lead single by Def Jam. Written by Bieber, Jason`` Poo Bear'' Boyd and Mason Levy, the song was produced by MdL and co-produced by Bieber. ``What Do You Mean? ''is a pop and tropical house song, with its instrumentation consisting in light flourishes of panpipes, looped vocal samples, piano chords, fervent synths, bass and`` slick beat'' elements with the sound of a clock ticking, while Bieber uses a smooth, soulful vocal. Lyrically, ``What Do You Mean? ''describes not being able to figure out the opposite sex with Bieber asking a girl why her body language is conflicting with her words.
Document 8: Out of the Woods (song): ``Out of the Woods ''is a song by American singer - songwriter Taylor Swift. The song was written and produced by Swift and Jack Antonoff of fun... It was the second song to be officially released from her fifth studio album 1989, serving as the first promotional single on October 14, 2014. It is the fourth track on the album, after`` Style''. ``Out of the Woods ''serves as the sixth official single with an accompanying music video that premiered on December 31, 2015, during Dick Clark's New Year's Rockin 'Eve on ABC. It was released to radio on February 5, 2016. The song went number one in Israel and has reached the top 10 in Belgium, Canada, and New Zealand as well as the top 20 in Australia and the United States.
Document 9: 22 (Taylor Swift song): ``22 ''is a song recorded by American singer - songwriter Taylor Swift for her fourth album, Red (2012). It was written by Swift along with Max Martin and Shellback. The song was released as the album's fourth single on March 12, 2013. The lyrics describe the joys of being 22 years old.
Document 10: Gorgeous (Taylor Swift song): Swift co-wrote ``Gorgeous ''with its producers Max Martin and Shellback. It has been described as a`` radio - friendly pop'' song. Lyrically, the song depicts ``the pursuit of a maddening love interest '', whom Swift describes as`` gorgeous''. Hugh McIntyre of Forbes characterized the production of the song as ``simultaneously a basic 808 drum and an attempt at something that pushes electro - pop into a more interesting territory than Top 40 is used to ''. Maeve McDermott of USA Today likened the chorus of the song to the sound of Katy Perry. According to Elle, the man mentioned in the song is the British actor Joe Alwyn, who is Swift's current boyfriend. The song is composed in the key of C major with a tempo of 92 beats per minute, with Swift's vocals spanning from C to F.
Document 11: Photograph (Ed Sheeran song): "Photograph" is a song recorded by the English singer-songwriter, Ed Sheeran, for his second studio album, "×" (2014). Sheeran wrote the song with Snow Patrol member, Johnny McDaid, who had a piano loop from which the composition developed. After recording several versions with other producers, Sheeran eventually solicited help from Jeff Bhasker; the collaboration generated a version that Bhasker further enhanced for months. The ballad derives its music primarily from an acoustic guitar, piano and programmed drums. With visually descriptive lyrics, it discusses a long-distance relationship inspired by Sheeran's own experience of being away from his then-girlfriend while he was on tour.
Document 12: Love Yourself: Answer: Love Yourself 結 'Answer' (stylized as LOVE YOURSELF 結 'Answer') is the third Korean - language compilation album by South Korean boy band BTS. The album was released on August 24, 2018 by Big Hit Entertainment and is available in 4 different versions: S, E, L, and F. The album contains twenty - five tracks (twenty - six for digital version), including seven new songs, with the track ``Idol ''serving as the lead single. Most tracks are from Love Yourself: Her, and Love Yourself: Tear, including some remixes. The album debuted at number one in South Korea, Canada and the United States, becoming BTS 'second chart - topping album in the US market.
Document 13: Back to December: ``Back to December ''is a song written and recorded by American singer / songwriter Taylor Swift for her third studio album Speak Now (2010). The song was sent to country radio in the United States on November 15, 2010, as the second single from Speak Now. According to Swift,`` Back to December'' is the first time she ever apologizes to someone in a song. Critics speculate that the song is about Taylor Lautner, Swift's ex-boyfriend, which was later acknowledged by Lautner. ``Back to December ''is considered an orchestral country pop ballad and its lyrics are a remorseful plea for forgiveness for breaking up with a former lover.
Document 14: Back to December: "Back to December" is a song written and recorded by American singer-songwriter Taylor Swift for her third studio album "Speak Now" (2010). The song was sent to country radio in the United States on November 15, 2010, as the second single from "Speak Now". According to Swift, "Back to December" is the first time she ever apologizes to someone in a song. Critics speculate that the song is about Taylor Lautner, Swift's ex-boyfriend, which was later acknowledged by Lautner. "Back to December" is considered an orchestral country pop ballad and its lyrics are a remorseful plea for forgiveness for breaking up with a former lover.
Document 15: We Are Never Ever Getting Back Together: After writing Speak Now (2010) entirely solo, Swift opted to collaborate with different songwriters and producers for Red. Thus, she called Max Martin and Shellback, two songwriters and producers whose work she admired, to discuss a possible collaboration. The trio conceived the concept for ``We Are Never Ever Getting Back Together ''shortly after a friend of Swift's ex-boyfriend walked into the recording studio and spoke of rumors he heard that Swift and her former flame were reuniting. After the friend left, Martin and Shellback asked Swift to elaborate on the details of the relationship, which she described as`` break up, get back together, break up, get back together, just, ugh, the worst''. When Martin suggested that they write about the incident. Swift began playing the guitar and singing, ``We are never ever... '', and the song flowed rapidly afterwards. She described the process as one of the most humorous experiences she had while recording, and said the musical partners matched her expectations. An audio clip of her sarcastically speaking about breakups can be heard before the final chorus. The song is reportedly about Swift's ex, Jake Gyllenhaal, as the two had broken up in January 2011 but had been seen on a date a few days later. After the release of the music video, more clues linking the song to Gyllenhaal emerged, with the actor looking like Gyllenhaal, the actor in the video giving her a scarf as Gyllenhaal had reportedly done for Swift and a bracelet Swift wears in the video that is speculated to look similar to that of which Gyllenhaal was rumored to have given Swift for her birthday.
ground_truth: ``Love Yourself ''
sub_queries: who sings everything has changed with taylor swift Answer: Ed Sheeran
what song did Ed Sheeran wrote for justin bieber Answer: ``Love Yourself ''