Question: Martin Hannett produced Joy Division's studio albums, who is the leader singer of Joy Division?
Context: Unknown Pleasures is the debut studio album by English rock band Joy Division, released on 15 June 1979 on Tony Wilson's Factory Records label.  The album was recorded and mixed over three successive weekends at Stockport's Strawberry Studios in April 1979 and was produced by Martin Hannett, who incorporated a number of unconventional recording and production techniques into the group's sound.  The cover artwork was designed by artist Peter Saville.  It is the only Joy Division album released during lead singer Ian Curtis's lifetime. Factory Records was a Manchester-based British independent record label, started in 1978 by Tony Wilson and Alan Erasmus, which featured several prominent musical acts on its roster such as Joy Division, New Order, A Certain Ratio, The Durutti Column, Happy Mondays, Northside, and (briefly) Orchestral Manoeuvres in the Dark and James.  Like the label 4AD Records, Factory Records used a creative team (most notably record producer Martin Hannett and graphic designer Peter Saville) which gave the label and the artists recording for it a particular sound and image.  The label employed a unique cataloguing system that gave a number not just to its musical releases, but to artwork and other objects, as well. Always Now is the debut studio album by Section 25.  It was released in September 1981 through iconic Manchester record label Factory with the catalogue number FACT 45.  The album was produced by Martin Hannett, best known for producing both of Joy Division's studio albums.  Joy Division front man Ian Curtis has been credited as co-producing the record, in parts produced before his death in May 1980.  Recording took place in February 1981 at Britannia Row Studios in Islington, London, owned by Pink Floyd. Control is a 2007 British biographical film about the life of Ian Curtis, singer of the late-1970s English post-punk band Joy Division.  It is the first feature film directed by Anton Corbijn, who had worked with Joy Division as a photographer.  The screenplay by Matt Greenhalgh was based on the biography "Touching from a Distance" by Curtis's widow Deborah, who served as a co-producer on the film.  Tony Wilson, who released Joy Division's records through his Factory Records label, also served as a co-producer.  Curtis' bandmates Bernard Sumner, Peter Hook, and Stephen Morris provided incidental music for the soundtrack via their post-Joy Division incarnation New Order.  "Control" was filmed partly on location in Nottingham, Manchester, and Macclesfield, including areas where Curtis lived, and was shot in colour and then printed to black-and-white.  Its title comes from the Joy Division song "She's Lost Control", and the fact that much of the plot deals with the notion that Curtis tried to remain James Martin Hannett (31 May 1948 – 18 April 1991), initially credited as Martin Zero, was an English record producer and an original partner/director at Tony Wilson's Factory Records.  Hannett produced albums by a range of artists, including Joy Division, the Durutti Column, Magazine, John Cooper Clarke, New Order and Happy Mondays.  His distinctive production style utilized unorthodox sound recording and technology, and has been described as sparse, spatial, and cavernous. Ian Kevin Curtis (15 July 1956 – 18 May 1980) was an English singer-songwriter and musician.  He is best known as the lead singer and lyricist of the post-punk band Joy Division.  Joy Division released their debut album, "Unknown Pleasures", in 1979 and recorded their follow-up, "Closer", in 1980. Closer is the second and final studio album by English rock band Joy Division.  It was released on 18 July 1980 on Factory Records, following the May 1980 suicide of lead singer Ian Curtis.  The album was produced by Martin Hannett.  After the posthumous release of Joy Division's non-album hit single "Love Will Tear Us Apart" in June 1980, the remaining members re-formed as New Order. "New Dawn Fades" is a song from the 1979 album "Unknown Pleasures" by Joy Division.  It opens with a backwards and heavily modified sample from previous song "Insight", presumably added by Martin Hannett, post-production.  The song relies on an ascending guitar riff by Bernard Sumner played against a descending bass riff by Peter Hook.  The song uses the same progression throughout, but grows in intensity as the song progresses, reaching its peak with Ian Curtis singing "Me, seeing me this time, hoping for something else", and ending with a guitar solo.  The song closes side one of "Unknown Pleasures".  It's also one of few Joy Division songs with two distinct guitars playing, one distorted and one a clean electric guitar picking notes from the guitar chords. The Invisible Girls were a British rock band, formed in Salford, Greater Manchester in 1978, to provide a musical backdrop to the recorded output of Salford punk poet John Cooper Clarke.  The band's nucleus was Joy Division and New Order producer Martin Hannett and keyboardist Steve Hopkins, with contributions from, amongst others, Pete Shelley of Buzzcocks and Bill Nelson of Be-Bop Deluxe.  The band also played on the first solo album by Pauline Murray (lead singer of Penetration), the eponymous "Pauline Murray and the Invisible Girls" and some singles, and later with Nico for the single "Procession". Martin Hannett's Personal Mixes is a compilation album by Joy Division, consisting of studio snippets and alternative mixes of Joy Division made by Martin Hannett, their producer.  The tapes of these sessions by Hannett were passed to Peter Hook who considered the outtakes and alternative versions to be an important part of Joy Division's recorded history.
Answer: Ian Curtis