Question: This British-Australian singer was a member of a rock duo which became associated with the members of what band?

full_context: Document 1: Trevor Lucas: Trevor George Lucas (25 December 1943 – 4 February 1989) was an Australian-born and United Kingdom-based folk artist, a member of Fairport Convention and one of the founders of Fotheringay. He mainly worked as a singer-songwriter and guitarist but also produced many albums and composed for the film industry toward the end of his career. He married three times, his first wife was Cheryl (1964–ca. 1969), his second wife was fellow folk musician Sandy Denny (1973–1978), and his third wife was Elizabeth Hurtt-Lucas (ca. 1979–89). Lucas died on 4 February 1989 of a heart attack in his sleep, in Sydney, aged 45. He was survived by Hurtt-Lucas, his daughter, Georgia Rose Lucas (by Denny), and his son, Clancy Hurtt-Lucas. According to Australia rock music historian, Ian McFarlane, Lucas "was one of the most acclaimed singer/songwriters Australia ever produced and although he was held in high regard in UK folk-rock circles, he remained virtually unknown in his homeland".
Document 2: Marianne Faithfull: Marianne Evelyn Gabriel Faithfull (born 29 December 1946) is an English singer, songwriter and actress. She achieved popularity in the 1960s with the release of her hit single "As Tears Go By" and became one of the lead female artists during the "British Invasion" in the United States.
Document 3: Bee Gees: were a pop music group formed in 1958. Their lineup consisted of brothers Barry, Robin, and Maurice Gibb. The trio were successful for most of their decades of recording music, but they had two distinct periods of exceptional success: as a popular music act in the late 1960s and early 1970s, and as prominent performers of the disco music era in the mid-to-late 1970s. The group sang recognisable three-part tight harmonies; Robin's clear vibrato lead vocals were a hallmark of their earlier hits, while Barry's R&B falsetto became their signature sound during the mid-to-late 1970s and 1980s. The Bee Gees wrote all of their own hits, as well as writing and producing several major hits for other artists.
Document 4: Trevor Gordon: Trevor Gordon Grunnill (5 May 1948 - 10 January 2013) was a British-Australian singer, songwriter and musician. He was a member of the late 1960s English group the Marbles, whose biggest hit was the UK No. 5 "Only One Woman".
Document 5: One Man Band (Roger Daltrey song): One Man Band is a song by The Who's lead singer, Roger Daltrey from his début solo album "Daltrey". The song was written by David Courtney and Leo Sayer, and features Daltrey's Acoustic guitar strumming. According to Daltrey, it "reminiscences of Shepherd's Bush" (A place in west London where Daltrey had grown up and The Who were formed) and became one the albums highlights of the album, and later being released as a single in its own right in some European territories.
Document 6: The Walls Fell Down: "The Walls Fell Down" is a second single by the English rock duo The Marbles, Lead vocals by Graham Bonnet it was released in March 1969, and it was written and produced by Barry Gibb, Robin Gibb, Maurice Gibb, of the Bee Gees, and was also produced by Robert Stigwood, it was recorded as a follow-up to "Only One Woman" but did not repeat the success of the previous single.
Document 7: Reg Presley: Reginald Maurice Ball (12 June 1941 – 4 February 2013), known professionally as Reg Presley, was an English singer-songwriter. He was the lead singer with the 1960s rock and roll band The Troggs, whose hits included "Wild Thing" and "With a Girl Like You" (they reached number one in the US and the UK respectively). He wrote the song "Love Is All Around", which was featured in the films "Four Weddings and a Funeral" and "Love Actually".
Document 8: Gordon Waller: Gordon Trueman Riviere Waller (4 June 1945 – 17 July 2009) was a British singer–songwriter–guitarist, best known as Gordon of the 1960s pop music duo Peter and Gordon, whose biggest hit was the No. 1 million-selling classic "A World Without Love".
Document 9: The Marbles (duo): The Marbles were an English rock duo that consisted of Graham Bonnet and Trevor Gordon, who operated between 1968 and 1969. Their only well-known singles were "Only One Woman" and "The Walls Fell Down". They also became associated with the Bee Gees members Barry, Robin and Maurice Gibb at that time.
Document 10: Carol Decker: 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
Document 11: Maurice Gibb: Maurice Ernest Gibb, CBE ( ; 22 December 1949 – 12 January 2003) was a singer, songwriter, multi-instrumenatalist and record producer, who achieved fame as a member of the pop group the Bee Gees. Although his brothers Barry and Robin Gibb were the group's main lead singers, most of their albums included at least one or two compositions by Maurice, including "Lay It on Me", "Country Woman" and "On Time". The Bee Gees were one of the most successful rock-pop groups ever. Gibb's role in the group focused on melody and arrangements, providing backing vocal harmony and playing a variety of instruments.
Document 12: The Gordons (duo): The Gordons are a folk music duo consisting of Gary Gordon and Roberta Gordon, who are husband and wife. They have been performing professionally since 1973.
Document 13: Maurice Gibb: Maurice Ernest Gibb, CBE ( ; 22 December 1949 – 12 January 2003) was a singer, songwriter, multi-instrumenatalist and record producer, who achieved fame as a member of the pop group the Bee Gees. Although his brothers Barry and Robin Gibb were the group's main lead singers, most of their albums included at least one or two compositions by Maurice, including "Lay It on Me", "Country Woman" and "On Time". The Bee Gees were one of the most successful rock-pop groups ever. Gibb's role in the group focused on melody and arrangements, providing backing vocal harmony and playing a variety of instruments.
Document 14: Turquoise (song): "Turquoise" is a song written and recorded by British singer-songwriter Donovan. The "Turquoise" single was released in the United Kingdom on October 30, 1965 through Pye Records (Pye 7N 15984) and charted, peaking at No.30. The "Turquoise" single was backed with "Hey Gyp (Dig the Slowness)" and only released in the United Kingdom. "Turquoise" was released as the b-side on "To Try for the Sun" in the United States. Interesting use of vibes in that song, played by
Document 15: Peter and Gordon: Peter and Gordon were a British pop duo, composed of Peter Asher (b. 1944) and Gordon Waller (1945–2009), who achieved international fame in 1964 with their first single, the million-selling transatlantic No.1 smash "A World Without Love". The duo had several subsequent hits in the British Invasion-era.
ground_truth: Bee Gees