Question: Which visual art movement involved the director of experimental films starring John Cale?
Context: John Cale is a Welsh musician, composer and record producer.  Although his main field is music (he composed original musical score for many films), he starred in several films as an actor.  It began in the sixties in various experimental films (mostly by Andy Warhol, but also by other directors).  In 1987, he received lessons from an actor F. Murray Abraham and subsequently played the role of a character named Hubbley in the short film "The Houseguest".  He later starred in several other films and television series.  As a composer, he composes mainly for French drama films.  He also participated in a variety of documentary films and television programs.  As a director he made one experimental film called "Police Car". Andy Warhol ( ; born Andrew Warhola; August 6, 1928 – February 22, 1987) was an American artist, director and producer who was a leading figure in the visual art movement known as pop art.  His works explore the relationship between artistic expression, celebrity culture, and advertising that flourished by the 1960s, and span a variety of media, including painting, silkscreening, photography, film, and sculpture.  Some of his best known works include the silkscreen paintings "Campbell's Soup Cans" (1962) and "Marilyn Diptych" (1962), the experimental film "Chelsea Girls" (1966), and the multimedia events known as the "Exploding Plastic Inevitable" (1966–67). Shifty Adventures in Nookie Wood is the fifteenth studio album by Welsh rock musician John Cale.  It was released on 1 October 2012 in Europe and 2 October in North America on the Double Six Records imprint of Domino Records.  It was released as digital download, heavyweight vinyl and CD.  Most of the songs were recorded by John Cale in his own studio in Los Angeles.  On one track he collaborated with Danger Mouse.  In September 2011 Cale released the "Extra Playful" EP and its release promised that the new album would be released the following year.  It is his first studio album since 2005's "blackAcetate". John Cale: Inside the Dream Syndicate Volume 2, Dream Interpretation, a.k.a. simply Dream Interpretation, is an album by John Cale from his tenure with the Theatre of Eternal Music.  It is the second in a loose anthology of minimalist pieces, once thought lost, compiled from the tape collection of fellow minimalist Tony Conrad.  The album follows Cale's debut collection "Sun Blindness Music" and the collaborative Dream Syndicate effort "Day of Niagara".  "Dream Interpretation" was in turn followed by "Stainless Gamelan". "If You Were Still Around" is a song by Welsh musician and composer John Cale.  It was written by John Cale together with playwright Sam Shepard.  It was originally released on Cale's 1982 album "Music for a New Society".  On 27 October 2014, a year after the death of his The Velvet Underground–bandmate Lou Reed, Cale released a new version of this song.  For this version was also released music video directed by Abigail Portner.  At the beginning of the video Cale is lying on the floor in a fetal position and after he views the photos of Reed and other deceased people associated with the Velvet Underground and The Factory: Sterling Morrison, Nico, Andy Warhol, and Edie Sedgwick. Concrete art is an art movement with a strong emphasis on abstraction.  The artist Theo van Doesburg, closely associated with the De Stijl art movement, coined the term "concrete art" as he in 1930 founded the group Art Concret and articulated its features in a manifesto titled "The Basis of Concrete Art", signed by four other artists of the group, including Otto G. Carlsund, Jean Hélion and Leon Tutundjian.  The manifesto explained that the resultant art should be non-referential insofar as its components should "not" refer to, or allude to, the entities normally encountered in the natural, visible world.  This is a distinction from abstraction generally.  In a more general sense "abstract art" could and often does include the "abstraction of forms in nature".  But "concrete art" was intended to emanate "directly from the mind" and consequently to be more "cerebral" than abstract art generally.  Concrete art is often composed of basic visual features such as planes, colors, and forms.  "Sentiment" tends to be absent from concrete art.  The "hand" of the artist may be difficult to detect in finished works of concrete art; concrete art may appear, in some instances, to have been made by a machine.  Concrete art often has a core visual reference to geometry whereas more general abstract art may find its basis in the components of the natural world.  A formulation of a description of concrete art might include a considerable reliance on the formal qualities of an artwork.  Theo Van Doesburg's manifesto stated that art "should receive nothing from nature's formal properties or from sensuality or sentimentality.  We want to exclude lyricism, dramaticism, symbolism, etc…."  In concrete art a mathematical equation can serve as a starting point.  Concrete art can include painting and sculpture. Adelaide Central School of Art is an independent, not-for-profit, accredited higher education provider of tertiary courses in the visual arts, located in Adelaide, Australia.  A single-focused art school, Adelaide Central School of Art offers training for students seeking to develop careers as professional practising artists.  In the studio-based teaching program, the school emphasises structured learning, practical skills and intellectual development.  All classes are led by lecturers who are leading practitioners in their field.  Students benefit from the range of experience and expertise offered by these respected contemporary artists, writers, and curators.  In addition to an associate degree of Visual Art, Bachelor of Visual Art, and Bachelor of Visual Art (Hons), the school offers a range of short courses, workshops and masterclasses. Lowbrow, or lowbrow art, describes an underground visual art movement that arose in the Los Angeles, California, area in the late 1970s.  It is a populist art movement with its cultural roots in underground comix, punk music, and hot-rod cultures of the street.  It is also often known by the name pop surrealism.  Lowbrow art often has a sense of humor – sometimes the humor is gleeful, sometimes impish, and sometimes it is a sarcastic comment. Close Watch: An Introduction to John Cale is the third compilation album by Welsh musician John Cale, released by Island Records in April 1999.  It featured songs from Cale's albums released between 1973 and 1996. "Northern Sky" is a song from the English singer-songwriter Nick Drake's 1970 album "Bryter Layter", produced by John Cale.  During the recording sessions for the album, the chronically shy and withdrawn songwriter formed a friendship and a mentorship of sorts with producer Joe Boyd.  Boyd was an early supporter of Drake, and saw commercial potential in the acoustic and unaccompanied demo version of the song, and recruited former Velvet Underground member John Cale to produce.  Cale added piano, organ and celesta arrangements, initially against Drake's wishes.
Answer: pop art