Question: What type of group does Umphrey's McGee and Iron Maiden have in common?

full_context: Document 1: Phish: Phish is an American rock band that was founded at the University of Vermont in 1983. The band is known for musical improvisation, extended jams, blending of genres, and a dedicated fan base. The current line-up—guitarist and lead vocalist Trey Anastasio, bassist and vocalist Mike Gordon, drummer and vocalist Jon Fishman, and keyboardist and vocalist Page McConnell—performed together for 15 years before going on hiatus from October 7, 2000, to December 30, 2002. They resumed touring from December 31, 2002 until August 15, 2004, when they announced that the Coventry Festival would be their last show. They reunited in March 2009 for a series of three consecutive concerts played in the Hampton Coliseum in Hampton, Virginia, and have since resumed performing regularly.
Document 2: The Iron Maidens: The Iron Maidens is an American heavy metal band from Los Angeles, California. Formed in 2001 as an all-female tribute act to English heavy metal band Iron Maiden. Considered the "World's Only Female Tribute to Iron Maiden," the band currently consists of vocalist Kirsten Rosenberg, bassist Wanda Ortiz, drummer Linda McDonald, guitarist Courtney Cox, and guitarist Nikki Stringfield,
Document 3: List of Iron Maiden concert tours: Iron Maiden are a British heavy metal band, founded in 1975 by bassist Steve Harris in London, England. After several personnel changes in the 1970s, the band settled on a lineup of Harris, Paul Di'Anno (lead vocals), Dave Murray (lead and rhythm guitars), Dennis Stratton (backing vocals, lead and rhythm guitar) and Clive Burr (drums), before they set out on their first professional tour, the Metal for Muthas Tour which supported the compilation album of the same name. After taking on a supporting slot with Judas Priest on their British Steel Tour and setting out on their own headline tour in support of their debut album, "Iron Maiden", the band supported Kiss on the European leg of their Unmasked Tour, following which Stratton was dismissed because of musical differences. Guitarist Adrian Smith was hired, following which Iron Maiden set out on a short series of UK dates before recording their second studio album, "Killers".
Document 4: Led Zeppelin: Led Zeppelin were an English rock band formed in London in 1968. The group consisted of guitarist Jimmy Page, singer Robert Plant, bassist and keyboardist John Paul Jones, and drummer John Bonham. The band's heavy, guitar-driven sound has led them to be cited as one of the progenitors of heavy metal, though their unique style drew from a wide variety of influences, including blues, psychedelia, and folk music.
Document 5: Umphrey's McGee: Umphrey's McGee is an American jam band originally from South Bend, Indiana. The band's approach shares many elements with groups like Phish and the Grateful Dead such as varying set lists, improvisation, playing two sets per night, and allowing fans to tape concerts, they are much more influenced musically by progressive rock artists such as King Crimson, Yes, Pink Floyd, Frank Zappa, The Mahavishnu Orchestra, and early Genesis, as well as heavy metal bands such as Iron Maiden and Van Halen. The band also identifies The Police, The Beatles, and Led Zeppelin as primary influences. UM experiments with many musical styles, including rock, metal, funk, jazz, blues, electronic, bluegrass, and folk.
Document 6: Bruce Dickinson discography: Bruce Dickinson, a British heavy metal singer, has released six studio albums, two live albums, one compilations, ten singles, three video albums, fourteen music videos, and one box set. In 1979, after playing in local groups, Dickinson joined hard rock band Samson. He departed after two years to become Iron Maiden's lead vocalist. His debut with this band is considered a "masterpiece", which was followed with a series of top-ten releases. In 1989, while Iron Maiden were taking a year off, Dickinson and former Gillan guitarist, Janick Gers, composed a song for . His solo debut, "Tattooed Millionaire" (1990), was an effort that favoured a hard rock/pop metal approach, different from what fans assumed would be an aggressive, Iron Maiden-like album. Four songs—the title track, "Dive! Dive! Dive!", "Born in '58", and a cover version of David Bowie's "All the Young Dudes"—were released as singles. Dickinson returned to Iron Maiden, accompanied by Gers as the new guitarist, and the project went on hiatus. "Dive! Dive! Live!" was a live video recorded from a concert in Los Angeles, California, in August 1990, and released in July 1991.
Document 7: Characteristics of progressive rock: Progressive rock is subgenre of rock music that developed in the United Kingdom and United States throughout the mid to late 1960s. Progressive rock, which initially had classical music influences, has come to include other fusions of music styles including jazz fusion, metal and folk rock musics. Progressive rock is an approach that combines elements of diverse styles. Jerry Ewing, editor of "Prog Magazine", explains that "Prog is not just a sound, it's a mindset." Dream Theater guitarist John Petrucci outlines that Progressive rock is defined by its very lack of stylistic boundaries. The advent of the concept album, plus the genre's roots in psychedelia, led albums and performances to be viewed as combined presentations of music, lyrics, and visuals.
Document 8: Greensky Bluegrass: Greensky Bluegrass is a five-piece American bluegrass/rock band founded in Kalamazoo, Michigan in 2000. The band has evolved over the years, growing from 3 to 5 members, adding electric effects and touring with a full light show. "The whole notion of “traditional bluegrass” strangely remains a sticking point for plenty of the genre's faithful. Partly because of their name, every article written about the band addresses the fact that what Greensky does is “not quite” bluegrass. These depths have been plumbed. In fact, in their own promotional material, GSBG describes their sound as “their own version of bluegrass music, mixing the acoustic stomp of a stringband with the rule-breaking spirit of rock & roll.” Greensky Bluegrass is known for their improvisation, multiple set shows, and open audience recording policy (akin to Phish and The Grateful Dead) and have broken through to a multi genre fanbase covering songs from Bruce Springsteen, Aerosmith, John Hartford, Dawes, Phish, The Grateful Dead, Rolling Stones, Prince and more.
Document 9: List of avant-garde metal artists: This is a list of avant-garde metal artists, regional scenes, and record labels. Avant-garde metal or avant-metal, also known as experimental metal, is a subgenre of heavy metal music loosely defined by use of experimentation and characterized by the use of innovative, avant-garde elements, large-scale experimentation, and the use of non-standard and unconventional sounds, instruments, song structures, playing styles, and vocal techniques. It evolved out of progressive rock and various forms of metal, including extreme metal, particularly the extreme subgenre death metal. Some early examples are the King Crimson releases "Larks' Tongues in Aspic" and "Red" in 1973 and 1974 respectively, and the 1976 Led Zeppelin album "Presence". The genre emerged in the early 1980s through the efforts of bands such as Celtic Frost and Voivod, who pioneered the genre. Other pioneers of avant-garde metal include Boris, Earth, Helmet, maudlin of the Well, Neurosis, Sunn O))), and Mr. Bungle. In the late 1990s, Misanthropy Records emerged as a promoter of Norwegian avant-garde metal until it folded in 2000, and, according to Jeff Wagner, in the late 1990s and early 2000s, a so-called "new wave of avant-garde metal" was spearheaded by The End Records. Some other record labels which promote avant-garde metal are Aurora Borealis, The Flenser, Holy Records, Hydra Head Records, Ipecac Recordings, Napalm Records, the Relapse Entertainment imprint of Relapse Records, Seventh Rule Recordings, and Southern Lord Records. In the United States, local avant-garde metal scenes have emerged in the San Francisco Bay Area, with bands such as Giant Squid, Grayceon, and Ludicra, Boston, with bands such as Isis, Kayo Dot, and maudlin of the Well and Seattle. According to the "New York Times", some regional scenes that developed in the mid-1990s included the cities of Tokyo, Los Angeles, and Oslo.
Document 10: Iron Maiden: Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. The band's discography has grown to thirty-eight albums, including sixteen studio albums, eleven live albums, four EPs, and seven compilations.
Document 11: List of Iron Maiden band members: Iron Maiden are a British heavy metal band formed in 1975 by bassist Steve Harris. After several lineup changes prior to their recording career, they settled on Harris, vocalist Paul Di'Anno, guitarist Dave Murray and drummer Doug Sampson. The band released an EP as a four-piece, before hiring guitarist Dennis Stratton in 1979. Doug Sampson was dismissed from the band as he was unable to cope with the touring schedule and, at the suggestion of Stratton, replaced by Clive Burr, with whom the band recorded their self-titled debut album in 1980. Later that year, Stratton was replaced by guitarist Adrian Smith, due to musical and personal differences brought about by choosing not to travel with the band when supporting Kiss on the European leg of their Unmasked Tour.
Document 12: List of songs recorded by Iron Maiden: Iron Maiden are an English heavy metal band formed by bassist Steve Harris in 1975. The band's first album, 1980's "Iron Maiden", was written primarily by Harris, with vocalist Paul Di'Anno co-writing two tracks and guitarist Dave Murray contributing "Charlotte the Harlot". The 1981 follow-up, "Killers", was written almost entirely by the bassist, with frontman Di'Anno contributing only to the title track, "Killers" (the North American bonus track "Twilight Zone" was credited to Harris and Murray). Bruce Dickinson replaced Di'Anno after the release of "Killers", although he did not contribute any songwriting to "The Number of the Beast", released in 1982, which featured three songs co-written by guitarist Adrian Smith. "The Number of the Beast" also spawned Iron Maiden's first UK Singles Chart top ten in the form of "Run to the Hills", which charted at number seven on its release. It was not until 1983's "Piece of Mind" that the songwriting process became a more varied and collaborative approach, with just four of its nine tracks being credited solely to Harris, two to Dickinson and Smith, one to Harris and Murray, one to Dickinson alone, and one to Harris, Dickinson, and Smith. The Dickinson and Smith-penned "Flight of Icarus" was the first Iron Maiden single to chart in the United States, reaching number eight on the "Billboard" Mainstream Rock chart.
Document 13: Iron Maiden (album): Iron Maiden is the debut studio album by the English heavy metal band Iron Maiden. It was issued by EMI on 14 April 1980 in the UK, and a few months later in North America, originally on Harvest/Capitol Records and subsequently Sanctuary Records/Columbia Records in the US. The North American version also included the song "Sanctuary", previously released in the UK as a non-album single. In 1998, along with the rest of the band's pre-1995 releases, "Iron Maiden" was remastered with "Sanctuary" added in all territories (but 2015 digital releases and all vinyl reissues use original tracklisting around the globe). It is the band's only album to feature guitarist Dennis Stratton.
Document 14: Jam band: Jam bands are musical groups whose live albums and concerts relate to a unique fan culture that began in the 1960s with the Grateful Dead, and continued with The Allman Brothers Band, which had lengthy jams at concerts. The performances of these bands typically feature extended musical improvisation ("jams") over rhythmic grooves and chord patterns, and long sets of music that can often cross genre boundaries. The Grateful Dead continued to grow their fanbase in the second half of the 1980s. In the mid-1980s the bands Phish, Edie Brickell & New Bohemians, Blues Traveler, Ozric Tentacles, Widespread Panic, Bela Fleck and the Flecktones, Spin Doctors, Col Bruce Hampton and Aquarium Rescue Unit, began touring with Jam band-style concerts. In the early 1990s and 2000s, a new generation of bands was spurred on by the Grateful Dead's touring and the increased exposure of The Black Crowes, My Morning Jacket, Dave Matthews Band, Widespread Panic and Aquarium Rescue Unit.
Document 15: King Crimson: King Crimson are an English rock band formed in London in 1968. The band has undergone numerous formations throughout its history of which 21 musicians have been members; since January 2017 it has consisted of Robert Fripp, Jakko Jakszyk, Tony Levin, Mel Collins, Pat Mastelotto, Gavin Harrison, Bill Rieflin and Jeremy Stacey. Fripp is the only consistent member of the group, and is considered the band's leader and driving force. The band has earned a large cult following. They were ranked No. 87 on VH1's "100 Greatest Artists of Hard Rock".
ground_truth: band