Question: Both Isaac Slade and Elizabeth Fraser shared song writing and what other position in their respective bands or solo acts?

full_context: Document 1: Elizabeth Fraser: Elizabeth Davidson Fraser (born 29 August 1963), sometimes known as Liz Fraser, is a British singer, songwriter and musician from Grangemouth, Scotland, best known as the vocalist for the band Cocteau Twins. She has a soprano vocal range. She was described by critic Jason Ankeny as "an utterly unique performer whose swooping, operatic vocals relied less on any recognizable language than on the subjective sounds and textures of verbalized emotions". Her distinctive singing has received much critical praise; she was once described as "the voice of God." Her lyrics range from straightforward English to semi-comprehensible sentences (idioglossia) and abstract mouth music. For some recordings, she has said she used foreign words without knowing what they meant – the words acquired meaning for her only as she sang them.
Document 2: Cher: Cher ( ; born Cherilyn Sarkisian; May 20, 1946) is an American singer and actress. Sometimes referred to as the Goddess of Pop, she has been described as embodying female autonomy in a male-dominated industry. She is known for her distinctive contralto singing voice and for having worked in numerous areas of entertainment, as well as adopting a variety of styles and appearances during her five-decade-long career.
Document 3: Brandon Flowers: Brandon Richard Flowers (born June 21, 1981) is an American singer, songwriter and multi-instrumentalist. He is best known as the lead singer, keyboardist and occasional bass guitarist of the Las Vegas-based rock band The Killers, with whom he has recorded five studio albums.
Document 4: Sandi Patty: Sandra Faye "Sandi" Patty (born July 12, 1956) is an American Christian music singer, known for her wide vocal range and expressive flexibility which has led music critics to dub her "The Voice".
Document 5: Björk: Björk Guðmundsdóttir (] , born 21 November 1965), known as Björk ( ), is an Icelandic singer, songwriter, actress, record producer, and DJ. Over her four-decade career, she has developed an eclectic musical style that draws on a wide range of influences and genres spanning electronic, pop, experimental, classical, trip hop, IDM, and avant-garde styles. She initially became known as the lead singer of the alternative rock band The Sugarcubes, whose 1987 single "Birthday" was a hit on US and UK indie stations and a favorite among music critics. Björk embarked on a solo career in 1993, coming to prominence as a solo artist with albums such as "Debut" (1993), "Post" (1995), and "Homogenic" (1997), while collaborating with a range of artists and exploring a variety of multimedia projects.
Document 6: Isaac Brock (musician): Isaac Kristofer Brock (born July 9, 1975) is the lead singer, guitarist, banjoist, and songwriter for the American indie rock band Modest Mouse, as well as his side project band, Ugly Casanova. As a songwriter he is noted for wordplay and frequent use of metaphors, philosophical lyrics, themes of oppressive rural lifestyles, and certain phrases and sayings commonly used in the early to mid-20th century and in blue collar environments.
Document 7: The Fray: The Fray is an American pop rock band from Denver, Colorado. Formed in 2002 by schoolmates Isaac Slade and Joe King, they achieved success with the release of their debut album, "How to Save a Life" in 2005, which was certified double platinum by the RIAA and platinum in Australia, Canada, New Zealand and the UK. The Fray achieved national success with their first single, "Over My Head (Cable Car)", which became a top ten hit in the United States. The release of their second single, "How to Save a Life", brought the band worldwide fame. The song charted in the top three of the "Billboard" Hot 100 and was a top 5 single in Australia, Canada, Ireland, Italy, Spain, Sweden, and the United Kingdom.
Document 8: Isaac Slade: Isaac Edward Slade (born May 26, 1981) is an American musician and the lead vocalist, main songwriter, pianist and co-founder of Colorado-based rock band The Fray.
Document 9: Beth Gibbons: Beth Gibbons (born 4 January 1965) is an English singer and songwriter. She is the singer and lyricist for the English band Portishead.
Document 10: Tyler Joseph: Tyler Robert Joseph (born December 1, 1988) is an American singer, songwriter, multi-instrumentalist, record producer, and rapper. He is the lead vocalist for the musical duo Twenty One Pilots.
Document 11: Ed Sheeran: Edward Christopher Sheeran, {'1': ", '2': ", '3': ", '4': "} (born 17 February 1991) is an English singer-songwriter, guitarist, and record producer. He was born in Halifax, West Yorkshire, and raised in Framlingham, Suffolk. He attended the Academy of Contemporary Music in Guildford, Surrey, as an undergraduate from the age of 18 in 2009. In early 2011, Sheeran independently released the extended play, "No. 5 Collaborations Project". After signing with Asylum Records, his debut album, "+" (read as "plus"), was released on 9 September 2011 and has since been certified seven-times platinum in the UK. The album contains the single "The A Team", which earned him the Ivor Novello Award for Best Song Musically and Lyrically. In 2012, Sheeran won the Brit Awards for Best British Male Solo Artist and British Breakthrough Act.
Document 12: Cocteau Twins: Cocteau Twins were a Scottish rock band active from 1979 to 1997. The original members were singer Elizabeth Fraser, guitarist Robin Guthrie, and bassist Will Heggie, who was replaced by multi-instrumentalist Simon Raymonde in 1983. The group has earned much critical praise for its distinctive ethereal sound and the distinctive soprano vocals of Fraser, which often abandoned recognizable language altogether. They were associated with the UK label 4AD for much of their career.
Document 13: Anni-Frid Lyngstad: Anni-Frid Synni, Princess Reuss of Plauen (German: "Anni-Frid Synni, Prinzessin Reuß von Plauen" ; born Anni-Frid Synni Lyngstad, 15 November 1945), commonly known as Frida Lyngstad, or just by the mononym, Frida, is a Norwegian-born Swedish singer, songwriter, and environmentalist. Known for her warm personality, striking auburn hair and rich mezzo-soprano voice, she is best known as one of the lead singers of the Swedish pop band, ABBA.
Document 14: Fran Healy (musician): Francis "Fran" Healy (born 23 July 1973) is a Scottish musician. He is the lead singer and main songwriter of the band Travis, having written nearly all of the songs on their first six studio albums, with the 8th being more of a co-written work. He is based in Berlin. Healy released his debut solo album titled "Wreckorder" in October 2010, which featured Paul McCartney on bass.
Document 15: Cristina Scabbia: Cristina Adriana Chiara Scabbia (] ; born 6 June 1972) is an Italian singer and lyricist, best known as one of the two vocalists in the Italian Gothic metal band Lacuna Coil. She used to write an advice column in the popular rock magazine "Revolver", alongside musician Vinnie Paul. Scabbia is featured in a Megadeth song "À Tout le Monde (Set Me Free)". She also featured on "The Theory of Everything", an album from Arjen Anthony Lucassen's Ayreon project, with which she is cast as the Mother. She is also the featured artist in the Apocalyptica song "S.O.S. (Anything But Love)" and another version of the Alter Bridge song "Watch Over You". Her highest note ever hit is claimed to be an A7. Scabbia performed a duet with the Italian ex-singer of Linea 77 Emiliano Audisio on the track "Beautiful Lie" to be part of the soundtrack for the 2013 Italian film "Passione sinistra".
ground_truth: vocalist