Question: Christopher Amott and Karen Carpenter, have which mutual occupation?

Context paragraphs:
Christopher Amott: Christopher Amott (born 23 November 1977) is a Swedish guitarist and vocalist, younger brother of Michael Amott and founding member of the Swedish metal bands Arch Enemy and Armageddon.

Karen Carpenter (album): Karen Carpenter is the only eponymous solo project by singer/drummer Karen Carpenter, released on CD by A&M Records in 1996.

Carpenter Performing Arts Center: The Richard and Karen Carpenter Performing Arts Center in Long Beach, California is a theater that hosts a variety of events, including films, forums, and musical and theatrical performances.  The venue is located on the campus of California State University, Long Beach.  It was built in 1994 and has seating for 1,074.  The stage area was modeled after the New York State Theater of the Arts at Lincoln Center.  The Carpenter Performing Arts Center is named for Richard and Karen Carpenter, alumni of the university and donors to the center.

Karen Carpenter: Karen Anne Carpenter (March 2, 1950 – February 4, 1983) was an American singer and drummer, and part of the duo the Carpenters with her brother Richard.  She was critically acclaimed for her contralto vocals, and her drumming was praised by contemporary musicians and peers.

Michael Amott: Michael Amott (born 28 July 1969) is a Swedish guitarist, songwriter, founding member of the bands Arch Enemy, Spiritual Beggars, and Carnage, as well as a former member of the grindcore band Carcass.  He is the older brother of Christopher Amott.  Some major influences in his music have been Tony Iommi, Michael Schenker, Uli Jon Roth and Dave Mustaine.

Astor Fong: Astor Fong () is a Chinese singer-songwriter, recording artist and record producer from Hong Kong, she sings in English, Mandarin Chinese and Cantonese.  Several of her solo albums have charted in Hong Kong and Asia.  Astor was dubbed the "Karen Carpenter of Asia".  She is a lyric contralto with a wide vocal range that spanned about three octaves.  Astor sang all of the Carpenters' songs in her concert 2013 with same key of Karen Carpenter's which are rare in female artists in Asia.  As Astor has a good track record in both English and Chinese albums, she was dubbed "Queen of Audiophile" by authoritative audiophile magazine in 2015.

The Karen Carpenter Story: The Karen Carpenter Story is an American television film about singer Karen Carpenter and the brother-and-sister pop music duo of which she was a part, The Carpenters.  The film aired on CBS on January 1, 1989.  Directed by Joseph Sargent, it starred Cynthia Gibb as Karen Carpenter, and Mitchell Anderson as her brother, Richard Carpenter.

Superstar: The Karen Carpenter Story: Superstar: The Karen Carpenter Story is a 1987 American short biographical film directed by Todd Haynes, co-written and co-produced by Haynes and Cynthia Schneider, and follows scenes from the final seventeen years of Karen Carpenter's life.  The film was withdrawn from circulation in 1990 after Haynes lost a copyright infringement lawsuit filed by Karen's brother and musical collaborator, Richard Carpenter.  The film's title is derived from The Carpenters' 1971 hit song, "Superstar".

If I Had You (The Carpenters song): "If I Had You" is a song recorded by singer Karen Carpenter during her solo sessions in New York with producer Phil Ramone for her subsequently shelved debut solo album.  In 1989 "If I Had You" was released as a Karen Carpenter solo single (featuring Richard Carpenter's remix ending), along with "The Uninvited Guest" (an outtake from the Carpenters album "Made In America"), also credited as a Karen Carpenter solo, as its B-side (in Japan the B-side was "Lovelines", another track from Karen's solo album, also the title track from the 1989 Carpenters "Lovelines" album).  The single was the first single from the Carpenters' album "Lovelines".  As of 2016, this is also the last Carpenters single released to American radio.  The single version has also appeared on numerous Carpenters compilations since its release.  The single reached number 18 on the 'Billboard" Adult Contemporary Chart.

Looking for Love (Karen Carpenter song): "Looking for Love" is a song released under Karen Carpenter's name.  It is regarded to be the first release by what was to become The Carpenters.  The music was written by Karen's brother, Richard Carpenter.  It was recorded in 1966 and released on record label Magic Lamp, a small label with a limited budget.  Even though Richard Carpenter does participate on the recording, it is printed "Karen Carpenter" on the recording contract and record label.

Supporting paragraphs: Christopher Amott Karen Carpenter
Answer: singer