Question: What role in their respective bands do Stephen Christian and Jonathan Davis share?

full_context: Document 1: Devin Townsend: Devin Garrett Townsend (born May 5, 1972) is a Canadian musician, songwriter and record producer. He founded extreme metal band Strapping Young Lad and was its primary songwriter, vocalist, and guitarist in from 1994 to 2007, and has an extensive career as a solo artist.
Document 2: Mike Davis (guitarist): Mike Davis (born ca. 1970) is an American metal guitarist. He is best known for his work in the progressive death metal band Nocturnus. He joined the band around 1988, and eventually became the bands' standout lead guitarist. He joined the band when he was just 18 years old and is widely regarded as an underrated guitarist. After the second breakup of Nocturnus in 2003 he formed the band Tiwanaku with Emo Mowery and Richard Christy, but quit early on 
Document 3: Kevin Max: Kevin Max (born August 17, 1967) is an American singer, songwriter, and poet. He is best known for being a member of the Christian pop group DC Talk. As a solo artist following the 2001 dissolution of DC Talk, he has recorded eight full-length studio albums, one Christmas album, and seven EPs, with one releasing in July. From 2012 until 2014, he was the lead singer of the band Audio Adrenaline.
Document 4: Stephen Christian: Stephen Christian is an American singer and songwriter best known as the former lead vocalist of the alternative rock band Anberlin, as well as the vocalist of his acoustic side-project Anchor & Braille. He and his bandmates started Anberlin in 2002, after the demise of their previous group, known as SaGoh 24/7. He is one of the main songwriters for Anberlin along with Joseph Milligan, and with the band has released seven albums, the final being in 2014. Many of the albums in the Anberlin discography have peaked in the top ten on various "Billboard" charts.
Document 5: Scott Stapp: Anthony Scott Flippen (born August 8, 1973), also known as Scott Stapp, is an American singer, songwriter, and musician, known as the lead vocalist and lyricist of rock bands Creed and Art of Anarchy. He also has two solo albums: "The Great Divide" (2005) and "Proof of Life" (2013).
Document 6: Steve Taylor: Roland Stephen "Steve" Taylor (born December 9, 1957), is an American singer, songwriter, record producer, music executive, film maker, and actor. A figure in what has come to be known as Christian alternative rock, Taylor enjoyed a successful solo career during the 1980s, and also served in the short-lived group Chagall Guevara. In contrast to many Christian musical artists, his songs have often taken aim at other Christians with the use of satirical, sardonic lyrics. In 1997, he founded the record label Squint Entertainment, which fueled the careers of artists such as Sixpence None the Richer, Chevelle, and Burlap to Cashmere. Despite this success, Taylor was ousted from the label by its parent, Word Entertainment, in 2001. He has produced and written for numerous musical acts, one of the most consistent being Newsboys. As a film-maker, Taylor co-wrote, directed, and produced the feature films "Down Under the Big Top", "The Second Chance", and "Blue Like Jazz". After a decade and a half of hiatus, Taylor returned to performing music in 2010 as the front-man for Steve Taylor & The Perfect Foil, a supergroup he founded with Peter Furler, Jimmy Abegg, and John Mark Painter.
Document 7: Faget (song): "Faget" is a song by the American nu metal band Korn. It is the sixth track from the band's self-titled debut studio album. The song is about how Korn's lead vocalist Jonathan Davis was bullied in high school for being into arts, wearing eyeliner, being into new wave music (for example, Duran Duran), and wearing frilly shirts. According to Jonathan Davis, he was constantly called names such as "faggot". Also, there was a rumor that Davis was gay. Jonathan Davis said he did not know if he was gay or not. Therefore, Davis tried to get in a relationship with another boy. However, Jonathan Davis disliked the experience, realizing he is not gay, even if people thought he was.
Document 8: Howard Jones (American musician): Howard Jones (born July 20, 1970) is an American metalcore vocalist, best known as vocalist of the bands Killswitch Engage and Blood Has Been Shed, and as the current vocalist of Light the Torch, formerly known as Devil You Know.
Document 9: Anchor &amp; Braille: Anchor & Braille is the recording alias for American singer and songwriter Stephen Christian, known for fronting the alternative rock band Anberlin, before its dissolution in 2014. Originally conceived as a side project for Christian, Anchor & Braille is now his primary vehicle for releasing music. Christian has described Anchor & Braille as a collaborative effort, having recorded with musicians such as Aaron Marsh of Copeland, Micah Tawlks, and Kevin Daily of Civil Twilight. Since its beginning, Christian has released three studio albums under this name, Felt in 2009, The Quiet Life in 2012, and Songs for the Late Night Drive Home in 2016.
Document 10: Jonathan Davis: Jonathan Howsmon Davis (born January 18, 1971), also known as JD and JDevil (or J Devil), is an American musician best known as the leading vocalist and frontman of the nu metal band Korn.
Document 11: Subseven: Subseven (styled as subseven) is a Christian rock band formed in 1999 in Weatherford, Oklahoma. They played in the Midwest for four years as an independent, where they released one album and one EP and gained a large local fan base. In 2003, they signed a record deal with Flicker Records and soon after released "". One year later they released their final album, "Free to Conquer". The band's members included Wesley Fite, Clint McManaman, Reed Corbin, Caleb Wilkerson and Jake Sullivan before their breakup in December 2005. They parted ways because they felt that God was calling the members on to new things. Ever since their breakup in 2005, the band members engaged in other musical activities, including bands and solo projects. In November 2007, their bass guitarist, Reed Corbin, died from a heart attack at the age of 33. As of 2015, they have, in some capacity, reunited.
Document 12: List of songs recorded by Korn: Korn is an American alternative metal band from Bakersfield, California. Formed in 1993, the band originally featured vocalist Jonathan Davis, guitarists James "Munky" Shaffer and Brian "Head" Welch, bassist Reginald "Fieldy" Arvizu, and drummer David Silveria. The current lineup of the group includes drummer Ray Luzier, who replaced Silveria in 2009. The band released its self-titled debut album "Korn" in 1994, which was produced by Ross Robinson and featured equal songwriting credits for the whole band. "Life Is Peachy", released in 1996, included two cover versions – of Ice Cube's "Wicked" and War's "Lowrider", while the band's third album "Follow the Leader" featured collaborations with Limp Bizkit's Fred Durst ("All in the Family") and rappers Ice Cube ("Children of the Korn") and Slimkid3 ("Cameltosis").
Document 13: Lil Jon: Jonathan Smith (born January 17, 1971), better known by his stage name Lil Jon, is an American rapper, record producer, and DJ. He was the frontman of the group Lil Jon & The East Side Boyz, which he formed in 1997, and they released several albums until 2004.
Document 14: Jonathan Davis and the SFA: Jonathan Davis and the SFA (Simply Fucking Amazings) is the solo band of Korn frontman Jonathan Davis.
Document 15: Steve Taylor &amp; The Perfect Foil: Steve Taylor & The Perfect Foil is an American alternative rock supergroup formed in 2010 by singer Steve Taylor with drummer Peter Furler (Newsboys, Peter Furler Band), guitarist Jimmy Abegg (Vector, A Ragamuffin Band), and bassist John Mark Painter (Fleming and John). Taylor formerly saw success as a new wave singer during the 1980s and early 1990s, and also fronted the short-lived band Chagall Guevara. However, by the mid-1990s he abandoned performing music and transitioned into work as a record producer, songwriter, and film-maker. In 2010 Taylor, who was frustrated at the slow pace of his fundraiser for his feature film "Blue Like Jazz", collaborated with Furler, Abegg, and Painter to record the song "A Life Preserved" for the film's soundtrack, and began recording other material. Taylor, Abegg, and Painter then featured on the Peter Furler song "Closer", under the name "Steve Taylor & Some Other Band", on Furler's album "On Fire". With those collaborations as a starting point, Taylor relaunched his career as a performing musician, and the lineup was branded as Steve Taylor & The Perfect Foil. The group released a studio album entitled "Goliath" on November 18, 2014 to critical acclaim and modest commercial success. In 2015, Daniel Smith of Danielson, with whom the band had been touring, temporarily joined on in a collaboration touted as Steve Taylor & The Danielson Foil. Under this incarnation, the group released the EP "Wow to the Deadness" on February 5, 2016, and toured until February 12.
ground_truth: vocalist