Question: Jim Berger and John Rich, have which shared occupation?

full_context: Document 1: Rescue Me (album): Rescue Me is an album by American country music artist John Rich, released in 2001. Though "Rescue Me" was released before Rich's album "Underneath the Same Moon", it was not recorded until two years later. Rich was inspired to record the album after he met Katie Darnell, a cancer patient at Monroe Carell Jr. Children's Hospital at Vanderbilt in Nashville, Tennessee. Rich was visiting the hospital with a group of songwriters (including future Big & Rich collaborator Big Kenny) to sing Christmas carols for the children when Darnell offered to sing to Rich and Kenny. Darnell sang "Rescue Me", a song of her own composition, which impressed Rich and Kenny. They later asked for permission to record the song, which led to an album of the same name. The album was recorded at Sony/Tree Studios with 30 hours of studio time donated by the location. Though there was some local interest in the title track, specifically from Gerry House and WSIX-FM, the album was not released on a wide scale. Prior to her death in 2003, Darnell appeared with Rich on several national TV shows to play her song.
Document 2: Thomas Gabriel Fischer: Thomas Gabriel Fischer (born 19 July 1963), also known by his stage names of Tom G. Warrior and Satanic Slaughter, is a Swiss metal musician. He is considered to be one of the pioneers of the death metal style of singing, which resembles guttural growling. He led the groups Hellhammer and Celtic Frost, and today is the frontman of the band Triptykon.
Document 3: Underneath the Same Moon: Underneath the Same Moon is an album recorded by John Rich. The album was recorded in 1999, after Rich left from the country group Lonestar and before he joined Big Kenny in the duo Big & Rich. However, like Big Kenny's 1999 album "Live a Little", this album was not released until 2006, after Big & Rich had released their first album. Rich also self-released an album in 2001, "Rescue Me", though it was recorded after "Underneath the Same Moon."
Document 4: Rich Rocks: Rich Rocks is the first extended play (or "Six Pak," as referred to on the album cover) by American country music artist John Rich, one half of the duo Big & Rich. Rich co-wrote all of the songs on the EP with the exception of "Let Somebody Else Drive", which is a John Anderson cover. On four of the six tracks, Rich is introduced by a friend that is also in the music industry. Originally slated for a late 2010 release, it was pushed back to May 17, 2011 to coincide with the release of John Rich's other EP, "For the Kids". Reprise Records released both "Rich Rocks" and "For the Kids".
Document 5: Sigurd Wongraven: Satyr (born Sigurd Wongraven on 28 November 1975) is the vocalist, lead and rhythm guitarist, bassist, and keyboardist for the Norwegian black metal band Satyricon. He was a founding member of Satyricon (although the band had been around for a short length of time as Eczema without him) and have so far released eight albums, two demos, and a live DVD. He has also contributed to other bands such as Darkthrone, Eibon, Storm, Thorns, Black Diamond Brigade and Wongraven. About black metal, he stated "It, black metal, doesn't necessarily have to be all satanic as long as it's dark." He has recently been endorsed by ESP Guitars.
Document 6: Martin Bengtsson: Martin Bengtsson is a Swedish metal musician. He was a key part of the influential Swedish melodic death metal scene. He was a member of the melodic death metal band Arch Enemy between 1997 and 1998, and played bass guitar on their second album, Stigmata. He was also a member of Arch Enemy guitarist Christopher Amott's side project Armageddon in 1997.
Document 7: Big &amp; Rich discography: Big & Rich is an American country music duo founded by Big Kenny and John Rich. Signed to Warner Bros. Records in 2004, the duo has released five studio albums, four extended plays, two extended play/DVD combos, one greatest hits album and fifteen singles. Their 2004 debut, "Horse of a Different Color", is also their highest-selling album, certified 3× Platinum by the Recording Industry Association of America (RIAA) and gold by the Canadian Recording Industry Association (CRIA). 2005's "Comin' to Your City" is certified platinum by the RIAA, and 2007's "Between Raising Hell and Amazing Grace" is certified gold by the same. Their first EP/DVD combo, "Big & Rich's Super Galactic Fan Pak", is also certified platinum.
Document 8: Lonestar: Lonestar is an American country music group consisting of Richie McDonald (lead vocals, acoustic guitar), Michael Britt (lead guitar, background vocals), Dean Sams (keyboards, background vocals) and Keech Rainwater (drums, percussion). Before the group's foundation in 1992, both Rainwater and Britt were members of the group Canyon. John Rich (bass guitar, lead and background vocals) was a member until he left in 1998, and later became one half of the duo Big & Rich, as well as a Nashville songwriter and record producer. Between 2007 and 2011, McDonald exited the band for a solo career, with former McAlyster lead singer Cody Collins replacing him until McDonald rejoined.
Document 9: Jim Berger (singer): Jim Berger (born 19 May 1974) is a Swedish black metal singer who goes by the stage name All. His original project was Abruptum. He also performed in many side projects, including Ophthalamia, Vondur and War, usually with Tony Särkkä.
Document 10: Tony Särkkä: Tony Särkkä (15 December 1972 – 8 February 2017), who went by the stage name It, was a Swedish multi-instrumentalist of Finnish/native American descent who has played in many black metal bands. He played guitar, drums and bass guitar as well as doing vocals. He is joined by Jim Berger in many projects. His projects include Abruptum, Ophthalamia, Vondur, Incision, Brejn Dedd, War and 8th Sin. He also contributed guest vocals to Dissection's second album "Storm of the Light's Bane", and to Marduk's third album "Opus Nocturne". He was the founder of The True Satanist Horde in Sweden.
Document 11: Jens Kidman: Jens Kidman (born 8 June 1966) is a Swedish metal vocalist. He is best known for being the lead vocalist for the Swedish extreme metal band Meshuggah. He is famous for his very aggressive shouts and screams and for his unique stage presence.
Document 12: John Rich: John Rich (born January 7, 1974) is an American country music singer-songwriter. From 1992 to 1998, he was a member of the country music band Lonestar, in which he played bass guitar and alternated with Richie McDonald as lead vocalist. After departing from the band in 1998, he embarked on a solo career on BNA Records in the late 1990s, releasing two singles for the label and recording "Underneath the Same Moon", which was not released until 2006. In 2001, he self-released "Rescue Me", an album he was inspired to record by a cancer patient named Katie Darnell. By 2003, he joined Big Kenny to form the duo Big & Rich, who released three albums on Warner Bros. Records as well as ten singles, including the Number One "Lost in This Moment". After Big & Rich went on hiatus in 2007, Rich began work on a third solo album, "Son of a Preacher Man", which has produced two more chart singles. In 2011, Rich released two Extended Plays, "Rich Rocks" and "For the Kids" before re-establishing Big & Rich in 2012.
Document 13: Abruptum: Abruptum is a black metal and dark ambient solo side-project band from Sweden. It is run by Evil (Morgan Steinmeyer Håkansson) of Marduk, but the band was formed in 1989 by IT (a.k.a. Tony Särkkä). All (a.k.a. Jim Berger), Ext and Evil joined the band later. IT was one of the leaders of the True Satanist Horde, part of the Swedish Black metal scene. Euronymous, co-founder of Mayhem and founder of Deathlike Silence Productions, described Abruptum as "the audial essence of pure black evil".
Document 14: James Bergstrom: James Bergstrom is an American musician best known as the drummer for the band Second Coming. Before that, he played drums for the band Sleze (later renamed Alice N' Chains), which also featured future Alice in Chains vocalist Layne Staley.
Document 15: Live a Little (Big Kenny album): Live a Little is the first solo album by American singer Big Kenny, prior to his joining John Rich in the duo Big & Rich. Recorded in 1999 for Hollywood Records, the album was not released until 2005, after Big & Rich had released their debut album. Its release coincided with the release of Rich's previously-unreleased debut album "Underneath the Same Moon", also recorded in 1999 and released in 2006. Unlike Kenny's work within the country music genre with Big & Rich, "Live a Little" is a mixture between rock and pop. This album was followed by "The Quiet Times of a Rock and Roll Farm Boy" in 2009 and "Big Kenny's Love Everybody Traveling Musical Medicine Show Mix Tape, Vol. 1" in 2010.
ground_truth: singer