Question: Which American musician, composer, activist and filmmaker whose work is characterized by nonconformity, free-form improvisation, sound experiments and satire of American culture, has collaborated with American keyboard player Tommy Mars?

Context articles: Tommy Mars
Bobby Emmons
Keri Pickett
Frank Zappa
Naked Thunder
Jimmy Greenspoon
James Hooker (musician)
Steven Stapleton
Natalia Almada
Don Randi

Tommy Mars (born Thomas Mariano on October 26, 1951) is an American keyboard player known for his work with Frank Zappa.
Bobby Gene Emmons (February 19, 1943 – February 23, 2015) was an American keyboard player and songwriter.
 He was an active session musician in Memphis, Tennessee, on tracks by Elvis Presley, Willie Nelson and many others from the 1950s onward.
 His compositions included "Luckenbach, Texas (Back to the Basics of Love)", written with Chips Moman and recorded by Waylon Jennings; and "Love Me Like You Used To", co-written with Paul Davis and recorded by both Johnny Cash and Tanya Tucker.
Keri Pickett (born in 1959, Charleston, S.C.) is an award-winning American photographer, author and filmmaker whose work explores love, family and community.
 Pickett’s work "pulls subjects from the edges of public awareness to the center of the frame".
 Pickett was first exposed to photography as a child through her figure-skater/photographer uncle Roy Blakey and years later, as an adult, she made a film about his life.
 Pickett discovered her own love of photography in college and graduated with a B.A. degree in photography from Moorhead State University in Minnesota with minors in Art History and Women's Studies.
 After graduation in 1983, Pickett moved in with her photographer uncle Roy Blakey in New York for a short time while starting an internship under the direction of American photographer Fred W. McDarrah at Village Voice.
 In 1987, after Pickett was diagnosed with Burkett's lymphoma, a rare cancer characterized by the rapid growth of tumors in the body, she left New York and returned to her home in Minnesota to begin chemotherapy.
 During the two years of Pickett’s treatment, she concentrated on her photographic work: Kids Coping with Life-Threatening Illness.
 Where once she had thought she was too young to die, Pickett's paradigm shifted as she photographed and became friends with children in the hospital who were dying of cancer.
 Pickett says, "When I was on chemotherapy I was so upbeat and positive that this started coming out in my pictures.
 I was a positive example to people.
 I started taking photos of kids with life-threatening illnesses, and my work switched...I starting putting more of myself into the work."
Frank Vincent Zappa (December 21, 1940 – December 4, 1993) was an American musician, composer, activist and filmmaker.
 His work was characterized by nonconformity, free-form improvisation, sound experiments, musical virtuosity, and satire of American culture.
 In a career spanning more than 30 years, Zappa composed rock, pop, jazz, jazz fusion, orchestral and "musique concrète" works, and produced almost all of the 60-plus albums that he released with his band the Mothers of Invention and as a solo artist.
 Zappa also directed feature-length films and music videos, and designed album covers.
 Publications such as "Ultimate Classic Rock" and "The Independent" have described him as one of the most innovative and stylistically diverse rock musicians of his generation.
Naked Thunder is a 1990 solo album by Ian Gillan, released soon after his departure from Deep Purple in 1989.
 It features a varied selection of songs, with one of Gillan's most passionate and impressive performances on power ballad "Loving on Borrowed Time" and traditional field lament "No More Cane on the Brazos".
 It was also the first album to feature Ian Gillan's long time writing partner Steve Morris.
 "Naked Thunder" was produced by Leif Mases and features a number of notable guest musicians, including drummer Simon Phillips and former Grease Band keyboard player Tommy Eyre.
James Boyd "Jimmy" Greenspoon (February 7, 1948 – March 11, 2015) was an American keyboard player and composer, best known as a member of the band Three Dog Night.
James Hooker Brown Jr. (born July 20, 1948 in Winnsboro, South Carolina) is an American keyboard player and composer.
Steven Peter Stapleton (born 3 February 1957 in Finchley, London, England) is a British musician and the only constant member of experimental improv outfit Nurse with Wound.
 He is often seen as one of the pioneers of the British industrial music scene, alongside bands such as Throbbing Gristle, Coil and Psychic TV, although in his music he has explored a wide range of styles, including free-form improvisation, folk, and even Latin American dance rhythms.
Natalia Almada is a Mexican-American photographer and documentary filmmaker.
 Almada is a filmmaker whose work focuses on Mexican history, politics, and culture in insightful and poetic films that push the boundaries of how the documentary form addresses social issues.
 Her films include "El Velador" (2011), "El General" (2009), "All Water Has a Perfect Memory" (2001), and "Al Otro Lado" (2005), and her work has appeared at numerous national and international venues, including the Museum of Modern Art, the Sundance Film Festival, the Guggenheim Museum, the Munich International Film Festival, and the Cannes Directors’ Fortnight.
 She won the 2009 Sundance Directing Award Documentary for her film “El General”.
 She is a 2012 MacArthur Fellow and the first Latina filmmaker to win the award.
Don Randi (born 25 February 1937) is an American keyboard player, bandleader and songwriter.
 He has performed on innumerable recordings, including many as a session musician and member of the Wrecking Crew, as well as releasing his own jazz records.