Question: "Happily" is a song by English-Irish boy band One Direction co-written by a band member who madehis debut as a singer with which band ?

Context articles: Midnight Memories (song)
What a Feeling (One Direction song)
Live While We're Young
Happily (song)
Harry Styles
One Direction: Where We Are – The Concert Film
What Makes You Beautiful
Up All Night Tour
Moments (One Direction song)
Strong (One Direction song)

"Midnight Memories" is a song by the English-Irish boy band One Direction from their third studio album of the same name.
 It was co-written by Julian Bunetta, Jamie Scott, John Ryan and band members Liam Payne and Louis Tomlinson.
"What a Feeling" is a song recorded by English-Irish boy band One Direction for their fifth studio album, "Made in the A.M." (2015).
 It was written and produced by Jamie Scott and co-written by Liam Payne, Louis Tomlinson, Daniel Bryer and Mike Needle.
 The song was released as the album's second promotional single on iTunes Store and Spotify on 11 November 2015.
 The song, along with the rest of "Made in the A.M.", leaked on the internet after a mishap in security during a listening party.
"Live While We're Young" is a song by English-Irish boy band One Direction, released as the lead single from their second studio album, "Take Me Home" (2012).
 Written by Savan Kotecha and its producers, Rami Yacoub and Carl Falk, the number was released by Syco Records on 28 September 2012.
 Falk, Kotecha, and Yacoub had collaboratively helmed One Direction's previous hits, "What Makes You Beautiful" and "One Thing".
 The track is an uptempo, upbeat bubblegum pop song which features rock undertones, vocal harmonies, hand claps, prominent electric guitar riffs, and repetitive synthesizers.
 The chorus of the song is predominantly featured alongside the bridge, and is backed by wordless chants.
 Its opening guitar riff bears similarities with The Clash's 1982 single, "Should I Stay or Should I Go".
"Happily" is a song by English-Irish boy band One Direction from their third studio album, "Midnight Memories" (2013).
 It was co-written by band member Harry Styles.
Harry Edward Styles (born 1 February 1994) is an English singer, songwriter, and actor.
 He made his debut as a singer with his band White Eskimo, who performed locally in Holmes Chapel, Cheshire.
 Styles rose to stardom as a member of the boy band One Direction, formed in 2010 through the British music competition series "The X Factor".
 One Direction has released five albums, performed four worldwide tours, and won several awards.
One Direction: Where We Are – The Concert Film, also known as One Direction: Where We Are - Live from San Siro Stadium is the second concert film by English-Irish boy band One Direction and the sequel to "".
 The film takes place during the 28 and 29 June 2014 shows of the band's Where We Are Tour at San Siro Stadium in Milan, Italy.
 It contains a 15-minute interview with the band with exclusive behind-the-scenes footage.
"What Makes You Beautiful" is a song by English-Irish boy band One Direction.
 It served as their debut single and lead single from their debut studio album, "Up All Night" (2011).
 Written by Savan Kotecha and producer Rami Yacoub, the song was released by Syco Records on 11 September 2011.
 The uptempo power pop track features a prominent guitar-based chorus and riff.
 The middle eight consists of a "na na na" hook while the opening guitar riff interpolates The McCoys's 1965 single "Hang on Sloopy".
The Up All Night Tour was the first headlining concert tour by English-Irish boy band One Direction, showcasing their debut album, "Up All Night" (2011).
 It began in December 2011 and was One Direction's first solo tour after being formed in the seventh series of "The X Factor" and being signed to Syco Records.
 The concert tour was announced in September 2011, with the initial British and Irish dates being revealed.
 The concert tour was managed by Modest!
 Management, the shows were backed by a five-piece musical band, and the creative assessments were handled by Caroline Watson and Lou Teasdale, among others.
 After the initial concert tour concluded in January 2012, shortly afterwards, the concert tour expanded with legs in Oceania and North America.
 They ultimately played over 60 shows in Europe, Oceania and North America.
"Moments" is a song by English-Irish boy band One Direction from their debut studio album, "Up All Night" (2011).
 It was written by Ed Sheeran, and Si Hulbert, the song's producer.
 In 2011, as One Direction member Harry Styles told Sheeran that the boy band did not have enough songs for their album, Sheeran offered "Moments" as a track that Sheeran "was never going to use".
"Strong" is a song by English-Irish boy band One Direction, taken from their third studio album "Midnight Memories" (2013).
 It was released on 20 November 2013.
 It reached number one in New Zealand, number 15 in Austria and number 44 in Canada.
 It was co-written by Louis Tomlinson