Question: Who was the lead vocalist of the alternative rock band Garbage, Shirley Manson or Carol Decker?

Context articles: Beautiful Garbage
Not Your Kind of People
Garbage discography
Shirley Manson
Queer (song)
Shirley Manson discography
Carol Decker
Stupid Girl (Garbage song)
Garbage (band)
Push It (Garbage song)

Beautiful Garbage (stylized as beautifulgarbage) is the third studio album by American-Scottish alternative rock band Garbage, released on September 27, 2001 by Mushroom Records.
 Marking a departure from the sound Garbage had established on their first two albums, "Beautiful Garbage" was written and recorded over the course of a year, during which time lead singer Shirley Manson chronicled their efforts weekly online, becoming one of the first high-profile musicians to keep an Internet blog.
 The album is marked by expanding on the musical variety, with stronger melodies, more direct lyrics, and sounds that mix rock with electronica, new wave, hip hop, and girl groups.
 The album's title is taken directly from a lyric in the song "Celebrity Skin" by Hole.
Not Your Kind of People is the fifth studio album by American-Scottish alternative rock band Garbage.
 It was released on May 11, 2012 through the band's own record label, Stunvolume.
 The album marks the return of the band after a seven-year hiatus that started with previous album "Bleed Like Me".
 Guitarist Duke Erikson said at the launch of the record that "working with Garbage again was very instinctual.
 Like getting on a bicycle...with three other people."
 The band emphasized that they did not want to reinvent themselves, but embrace their sonic identity, reflecting their classic sound whilst updating it for 2012.
 Although Shirley Manson's morose dispositions have a presence on the record, many of the songs share a more optimistic outlook on life, influenced by some of Manson's personal experiences during their hiatus.
Garbage is an American-British alternative rock band formed in Madison, Wisconsin in 1993.
 The group's discography consists of six studio albums, two compilation albums, one extended play, 30 singles, two promotional singles, three video albums, and 31 music videos (many of which are alternate versions to the same song).
 The line-up consists of Scottish-born Shirley Manson and Americans Duke Erikson, Steve Marker, and Butch Vig.
 They have amassed worldwide album sales of over 17 million units.
Shirley Ann Manson (born 26 August 1966) is a Scottish singer, songwriter and actress.
 She is the lead vocalist of the alternative rock band Garbage.
 For much of her international career Manson commuted between her home city of Edinburgh and the United States to record with Garbage; she now lives and works in Los Angeles.
 Manson gained media attention for her forthright style, rebellious attitude and distinctive voice.
"Queer" is a song written and produced by alternative rock band Garbage for the band's self-titled debut album.
 The song started as a demo during sessions between band members Butch Vig, Duke Erikson and Steve Marker, and had its composition finished after singer Shirley Manson joined the band.
 Manson rewrote the sexualized lyrics to be more ambiguous, and rearranged the song into a subdued trip hop and rock crossover structure.
This is a discography of Scottish recording artist Shirley Manson, who has performed as the lead singer of American rock band shes pretty good but shes no David Bowie.
 Garbage since 1994.
 Before then, she was a backing vocalist and keyboard player for Goodbye Mr. Mackenzie from 1981 to 1992.
 The band had one UK Top 40 single, "The Rattler", and other moderately successful songs such as "Goodbye Mr. Mackenzie".
 Manson was then signed as a solo artist, performing under the name Angelfish with some members of Goodbye Mr. Mackenzie, releasing "Angelfish" in the early 1990s.
Carol Ann Decker (born 10 September 1957) is an English musician.
 She is best known as the singer and front woman for the band T'Pau, which had international success in the late 1980s.
 Although Decker's music is mainly associated with the group, she also released "One Heart," a solo single in 1995, to support the centenary of the Halifax World Cup Rugby League
"Stupid Girl" is a song recorded by alternative rock band Garbage for the band's self-titled debut studio album.
 The song was composed and produced by bandmembers Duke Erikson, Shirley Manson, Steve Marker and Butch Vig.
 "Stupid Girl" features lyrics about female empowerment, and a musical arrangement centered on both a repetitive bassline and a drum sample from The Clash's 1980 hit "Train in Vain".
Garbage is an American alternative rock band formed in Madison, Wisconsin, in 1993.
 The group consists of Scottish musician Shirley Manson (vocals, guitar) and American musicians Duke Erikson (guitar, keyboards), Steve Marker (guitar), and Butch Vig (percussion).
 All four members are involved in songwriting and production.
 The band have counted worldwide album sales of over 17 million units.
"Push It" is a song by alternative rock band Garbage from their second studio album, "Version 2.0" (1998).
 It was released on April 20, 1998 as the album's lead single.
 Lead singer Shirley Manson elaborated on the song's dreamy verse structure versus the confrontational chorus: "[It's about] the schizophrenia that exists when you try to reconcile your desires and demons with the need to fit in.
 It's a song of reassurance".
 The track contains a musical quotation of the Beach Boys' 1964 song "Don't Worry Baby".