Question: Portishead and The Replacements, are which type of musical organization?

full_context: Document 1: Paul Westerberg: Paul Harold Westerberg (born December 31, 1959) is an American musician, best known as the lead singer, guitarist and songwriter in The Replacements, one of the seminal alternative rock bands of the 1980s. He launched a solo career after the dissolution of that band. In recent years, he has cultivated a more independent-minded approach, primarily recording his music at home in his basement.
Document 2: Trip hop: Trip hop (sometimes called "downtempo") is a musical genre that originated in the early 1990s in the United Kingdom, especially Bristol. It has been described as "a fusion of hip hop and electronica until neither genre is recognizable," and may incorporate a variety of styles, including funk, dub, soul, psychedelia, R&B, and house, as well as other forms of electronic music. Trip hop can be highly experimental.
Document 3: The Replacements (band): The Replacements were an American rock band formed in Minneapolis, Minnesota, in 1979. Initially a punk rock band, they are considered pioneers of alternative rock. The band was composed of the guitarist and vocalist Paul Westerberg, guitarist Bob Stinson, bass guitarist Tommy Stinson and drummer Chris Mars for most of its career. Following several acclaimed albums, including "Let It Be" and "Tim", Bob Stinson left the band in 1986, and Slim Dunlap joined as lead guitarist. Steve Foley replaced Mars in 1990. Towards the end of the band's career, Westerberg exerted more control over the creative output. The group disbanded in 1991, with the members eventually pursuing various projects. A reunion was announced on October 3, 2012. The Replacements never had significant commercial success, except for "I'll Be You", which hit number 1 on the "Billboard" Alt Rock chart, but they influenced numerous alternative rock acts.
Document 4: Let It Be (The Replacements album): Let It Be is the third studio album by American rock band The Replacements. It was released on October 2, 1984 by Twin/Tone Records. A post-punk album with coming-of-age themes, "Let It Be" was recorded by the band after they had grown tired of playing loud and fast exclusively as on their 1983 "Hootenanny" album; the group decided to write songs that were, according to vocalist Paul Westerberg, "a little more sincere."
Document 5: Portishead (band): Portishead are an English band formed in 1991 in Bristol. They are often considered one of the pioneers of trip hop music. The band are named after the nearby town of the same name, eight miles west of Bristol, along the coast. Portishead consists of Geoff Barrow, Beth Gibbons and Adrian Utley, while sometimes citing a fourth member, Dave McDonald, an engineer on their first records.
Document 6: Pixies: The Pixies are an American alternative rock band formed in 1986 in Boston, Massachusetts. Until 2013, the band comprised Black Francis (lead vocals, rhythm guitar), Joey Santiago (lead guitar), Kim Deal (bass, backing vocals) and David Lovering (drums). The band disbanded acrimoniously in 1993, but reunited in 2004. After Deal left in 2013, the Pixies hired Kim Shattuck as a touring bassist; she was replaced the same year by Paz Lenchantin, who became a permanent member in 2016.
Document 7: I Will Dare: "I Will Dare" is a song by American alternative rock band The Replacements, written by Paul Westerberg. The song was released as a single on independent record label Twin/Tone Records in July 1984, shortly before the release of the band's album "Let It Be" that October, on which the song served as the opening track. Allmusic writes that the song "stands as perhaps the band's most beloved song and is a touchstone for their mid-'80s heyday, not to mention its status in the jangle and college rock canons." The song has been included in The Rock and Roll Hall of Fame's 500 Songs that Shaped Rock and Roll.
Document 8: Nirvana (band): Nirvana was an American rock band formed by singer and guitarist Kurt Cobain and bassist Krist Novoselic in Aberdeen, Washington, in 1987. Nirvana went through a succession of drummers, the longest-lasting being Dave Grohl, who joined in 1990. Despite releasing only three full-length studio albums in their seven-year career, Nirvana has come to be regarded as one of the most influential and important alternative bands in history. Though the band dissolved in 1994 after the death of Cobain, their music maintains a popular following and continues to influence modern rock and roll culture.
Document 9: Massive Attack discography: The discography of British trip hop group Massive Attack consists of five studio albums, three compilation albums, five remix albums, one soundtrack album, five extended plays, eighteen singles and twenty-seven music videos. The group were founded in 1988 by musicians Robert "3D" Del Naja, Grantley "Daddy G" Marshall, Andrew "Mushroom" Vowles and Adrian "Tricky" Thaws in Bristol, England. Prior to the formation of Massive Attack, all three were members of British sound system The Wild Bunch.
Document 10: Soul Asylum discography: The discography of American rock band Soul Asylum consists of 11 studio albums, two live albums, five compilation albums, two extended plays (EPs), 22 singles, and 17 music videos. Formed in 1981 in Minneapolis, Minnesota using the name Loud Fast Rules, the band's original lineup consisted of vocalist Dave Pirner, guitarist Dan Murphy, bassist Karl Mueller, and drummer Pat Morley. The band changed their name to Soul Asylum prior to the release of "Say What You Will... Everything Can Happen" in 1984. Later that year, Morley was replaced on drums by Grant Young.
Document 11: Portishead (album): Portishead is the eponymous second studio album by English band Portishead, released in September 1997.
Document 12: 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 13: List of Foo Fighters band members: Foo Fighters is an American alternative rock band formed by multi-instrumentalist and vocalist Dave Grohl in 1994. After recording the album "Foo Fighters" alone, Grohl enlisted guitarist Pat Smear, bassist Nate Mendel and drummer William Goldsmith to join the band. This lineup recorded the second Foo Fighters album, 1997's "The Colour and the Shape", although most of Goldsmith's drum recordings were removed and re-recorded by Grohl for the release, after he left the band due to creative tensions. Goldsmith was replaced by Taylor Hawkins, and Franz Stahl replaced Smear after he also departed, although he only remained in the band for a short period and did not record an album with the group. The group's third album, "There Is Nothing Left to Lose", featured Hawkins on drums and was released in 1999.
Document 14: Massive Attack: Massive Attack are an English trip hop group formed in 1988 in Bristol, consisting of Robert "3D" Del Naja, Grant "Daddy G" Marshall and formerly Andy "Mushroom" Vowles ("Mush"). Their debut album "Blue Lines" was released in 1991, with the single "Unfinished Sympathy" reaching the charts and later being voted the 63rd greatest song of all time in a poll by "NME". 1998's "Mezzanine", containing "Teardrop", and 2003's "100th Window" charted in the UK at number one. Both "Blue Lines" and "Mezzanine" feature in "Rolling Stone"' s list of the 500 Greatest Albums of All Time.
Document 15: Portishead discography: The discography of British trip hop group Portishead consists of three studio albums, one live album, one compilation, ten singles and one video album. The Bristol-based band consists of Geoff Barrow, Beth Gibbons and Adrian Utley.
ground_truth: band