Question: Which musician is American, Roy Khan or Lou Gramm?

full_context: Document 1: Foreigner (Foreigner album): Foreigner is the debut studio album by the British-American rock band Foreigner, released on March 8, 1977. It spun off a barrage of hit singles, including "Feels Like the First Time", "Cold as Ice" and "Long, Long Way from Home". It also features album tracks such as "Headknocker" and "Starrider", the latter of which features a rare lead vocal from lead guitarist and co-founder Mick Jones. The first attempt at mixing the album was done at Sarm Studios, London, but dissatisfied with result the album was re-mixed at Atlantic Recording Studios by Mick Jones, Ian McDonald and Jimmy Douglass.
Document 2: Lou Gramm: Lou Gramm (born Louis Andrew Grammatico; May 2, 1950) is an American rock singer, and songwriter, best known for being the original lead singer of the British-American rock band Foreigner.
Document 3: Foreigner (band): Foreigner is a British-American rock band, originally formed in New York City in 1976 by veteran English musician Mick Jones and fellow Briton and ex-King Crimson member Ian McDonald along with American vocalist Lou Gramm.
Document 4: Black Sheep (rock band): Black Sheep, a Rochester, New York-based 1970s United States rock music band, was one of vocalist Lou Gramm's early working bands (it followed Poor Heart, which broke up c. 1970). The group, which had released the single "Stick Around" in 1974, the album "Black Sheep" in 1975, and the album "Encouraging Words" in late 1975, was no longer performing when Gramm was invited by Mick Jones to join the band Foreigner in 1976.
Document 5: Silverthorn (album): Silverthorn is the tenth studio album by the American power metal band Kamelot. The album was released on the Steamhammer label, a division of SPV, on October 2012 worldwide. It is the first album to feature Tommy Karevik as the lead singer and their third concept album, after "Epica" (2003) and "The Black Halo" (2005). The concept and story are original, and features a 19th-century little girl named Jolee, who dies in a tragic accident witnessed by her twin brothers. The story deals with how the girl's affluent family handles the tragic event, leading to cover-ups, secrets, and betrayal. The cover by Stefan Heilemann shows Jolee, the main character and angel of afterlife, as an adult.
Document 6: Mustis: Mustis is the pseudonym of Øyvind Johan Mustaparta (born 10 September 1979), a Norwegian keyboardist best known for his work in the symphonic black metal band Dimmu Borgir, as well as the black/thrash metal band Susperia. Mustis joined Dimmu Borgir in 1998 and has contributed to the further progression of their ambient, atmospherical, symphonic sound. This can be heard in songs such as "Progenies of the Great Apocalypse," which he composed, on their 2003 album, "Death Cult Armageddon". His other studio work with Dimmu Borgir includes "Spiritual Black Dimensions" (1999), "Puritanical Euphoric Misanthropia" (2001), and the re-release of "Stormblåst" (2005) and "In Sorte Diaboli" (2007). Mustis departed the band in 2009 and issued a statement in which he implied that he was being kept out of the proper registration for music he was writing. Due to this, according to his statement, he was fired by text message and he will be allowing "the resolution come from the lawyers instead of dealing with more dishonesty and lies on a one-on-one personal level."
Document 7: Shagrath: Stian Thoresen (born 18 November 1970) is a Norwegian musician best known as the vocalist, founding member and multi instrumentalist of Dimmu Borgir.
Document 8: Tommy Karevik: Tommy Karevik (born November 1, 1981) is a Swedish metal vocalist, best known as the singer for metal bands Seventh Wonder and Kamelot.
Document 9: Dirty White Boy (song): "Dirty White Boy" is a song recorded by British-American rock band Foreigner, written by Lou Gramm, Mick Jones, and produced by Roy Thomas Baker, Jones, and Ian McDonald. It was the first single taken from the band's third studio album, "Head Games" (1979). The B-side, "Rev On The Red Line" has also proven to be very popular among fans, but was never released as an A-side single on its own. Lou Gramm's trademark scream at the end of the song is missing from this abbreviated version of "Dirty White Boy". Jones has claimed that the song was about Elvis Presley, adding that "he always was that dirty white boy who changed the shape of music completely. It was talking about the kind of heritage that he left, and I think that had an effect on all the musicians that came after, like Mick Jagger - he was also a dirty white boy. Elvis paved the way for all that."
Document 10: Kamelot: Kamelot is an American power metal band from Tampa, Florida, formed by Thomas Youngblood and Richard Warner in 1991. The Norwegian vocalist Roy Khan joined for the album "Siége Perilous", and shared songwriting credit with Youngblood until his departure in April 2011. On June 22, 2012, Youngblood announced on their website that their new vocalist is the Swedish singer Tommy Karevik, who was first featured on Kamelot's album "Silverthorn" as main vocalist, co-songwriter and lyricist.
Document 11: That Was Yesterday (Foreigner song): "That Was Yesterday" was the second single taken from the album "Agent Provocateur" by the band Foreigner. This song was available in four versions, as a remixed single, a very popular extended remix, an orchestral version, and the original mix. The song was written by Lou Gramm and Mick Jones, and the B-side "Two Different Worlds" is also of note for being the first solo-written Lou Gramm song to appear on a single. The single reached number 12 on the "Billboard" Hot 100 chart, and also reached #4 on the Billboard Mainstream Rock chart and #24 on the Adult Contemporary chart. It also reached the Top 40 in the UK (#28), the Netherlands (#19), Switzerland (#29) and Germany (#31).
Document 12: Graham Bonnet: Graham Bonnet (born 23 December 1947) is an English rock singer and songwriter. He has recorded and performed as a solo artist and as a member of several hard rock and heavy metal bands including Rainbow, the Michael Schenker Group, Alcatrazz, and Impellitteri. Bonnet is known for his James Dean-inspired style and extremely powerful singing voice and wide vocal range. His singing has been noted as 'very loud' by both his contemporaries and himself, and he claims to be a self-taught singer with 'no discipline for lessons'.
Document 13: Midnight Blue (Lou Gramm song): "Midnight Blue" is the first single released by Lou Gramm from his debut solo album "Ready or Not" in 1987. The single spent five weeks at number one on the "Billboard" Hot Album Rock Tracks, starting on February 14, 1987, and peaked at number five on the "Billboard" Hot 100, Gramm's highest-charting solo hit.
Document 14: Roy Khan: Roy Sætre Khantatat (born March 12, 1970), is a Norwegian singer-songwriter. Commonly known as Roy Khan or simply Khan, he was the lead vocalist for the symphonic power metal band Kamelot from 1997 to his departure in 2011. He co-wrote most of Kamelot's songs with the band's guitarist and founder Thomas Youngblood during his tenure. Prior to joining Kamelot, Khan was lead singer for the Norwegian progressive metal band Conception from 1991 until 1997 when they disbanded.
Document 15: King ov Hell: Tom Cato Visnes (born November 27, 1974), better known as King ov Hell or simply King, is a Norwegian musician. He is best known as the former bassist of black metal band Gorgoroth, but he is also the co-founder of Ov Hell, God Seed, Jotunspor, Audrey Horne, Sahg, I and Temple of the Black Moon.
ground_truth: Lou Gramm