Al Hansen was best known as an early Fluxus, Happenings and Pop artist.
His informal way of life and his aversion to documenting his activities made Hansen the subject of many legends. One was that he spent most of 1965 riding the New York City subways. This was untrue, though he was indeed "making himself scarce'' over a legal matter. At the same time he was working on his only large book, A Primer of Happenings and Time/Space Art (1966), which was the most popular book on the field for many years.
Born in New York City, Hansen showed a talent for drawing from an early age, and as a teenager, together with James ''Jimbo'' Breslin, the journalist and a schoolmate, he published the Daily Flash, a newspaper for which Hansen drew cartoons. His career in journalism came to an abrupt end when he was drafted into the 82nd Airborne Division, in which he served from 1945 to 1948. He experienced in 1956 an epiphany of sorts when he was stationed in a bombed-out piano warehouse in Frankfurt am Main and was ordered to push a number of pianos off the edge of the top floor.
On his demobilisation Hansen's art interests developed both in purely visual terms and in event-making. He studied at Tulane University, the Art Students League, the Hans Hoffman School of Art and, after 1957, at Pratt Institute in Brooklyn. Here he was exposed to the music of John Cage. Finding it ''complete noise, a hopeless mess'' which he could not understand, he decided he must study with Cage, which he did in Cage's still-discussed course in ''Experimental Composition'' at New York's New School for Social Research in 1958 and 1959.
It was in Cage's class that I met Hansen and, along with George Brecht and Jackson Mac Low, and others, we performed in coffee shops around New York City, using the name "The Audio-Visual Group''. This climaxed in a performance of Hansen's Alice Denham in 48 Seconds on 7 April 1959, at New York's august Kaufman Auditorium of the 92nd Street YM-YWHA. The musicologist Paul Henry Lang, then the New York Herald Tribune critic, described it as a ''nightmarish show'', with the performers using toys and home-made instruments. Such pieces became, after 1962, the repertoire for the Fluxus group.
Through Cage's class Hansen met Allan Kaprow, James Dine and the other early Happenings artists, and he took part in shows and performances with them at the Reuben Gallery, the Living Theater and other venues in and around New York. Although most of the Happenings artists had slowed down or stopped performing by the mid-Sixties, Hansen kept going. In 1966, with the German Happenings artist Wolf Vostell, he placed advertisements in New York newspapers for ''Happenings in Your Home''. He performed in Alison Knowles's Cafe Au Gogo series in New York, my own The Tart at Sunnyside Gardens Boxing Arena (1966), and in his own works at the various incarnations (studio, gallery or whatever loft he happened to be living in) of his Third Rail Gallery, which ran from 1962 to 1969.
Hansen's visual work of the Fifties was mainly geometrical abstraction. He had a fine formal sense in spite of, or perhaps because of, his having complete red-green colour blindness. He understood, however, how colours were supposed to work and frequently invited friends to mix and label colours for him. As late as 1965 Hansen produced a series of irregularly shaped stretched canvases painted in bright, complementary colours, with mixed geometrical and popular culture imagery.
From 1960 Hansen turned increasingly to collage and constructions made out of detritus - Hershey chocolate-bar wrappers and cigarette butts for example, remained a principal focus for the rest of his life.
From the late 1970s, because of the increasing conservatism of the New York art world, Hansen spent more and more time in California and in Europe, first in Copenhagen and Amsterdam and finally in Cologne, where he had finally settled permanently by 1982.
His last American show was at the Gracie Mansion Gallery in 1989, but he also showed regularly at the Galerie Elisabeth Konig in Vienna. At the time of his death, the Poszti-Bott Gallery in Cologne was working with two German museums, organising a Hansen retrospective.
Good documentation of his work exists at the Henie Onstad Museum near Oslo, Norway (Hansen was partly of Norwegian descent), the Archiv Sohm in Stuttgart, Germany, and at the Getty Institute for the Arts and Humanities in Santa Monica, California.
Even to his death Hansen's capacity to inspire legend pursued him. As rumour had it, Hansen was sitting on a bar stool in a German pub drinking with a friend and perhaps lighting up a joint (actually Hansen did not smoke marijuana) when he sighed and fell off the stool dead. On the other hand, according to his daughter he went to a pub with friends, complained that he did not feel well and went home. A friend later found Al Hansen dead, presumably from a heart attack, behind a large portfolio which was beside his favourite chair to work in.