Background: Jean-Michel Basquiat was born in Brooklyn, New York, on December 22, 1960, shortly after the death of his elder brother, Max. He was the second of four children of Matilde Andrades (July 28, 1934 - November 17, 2008) and Gerard Basquiat (1930 - July 7, 2013). He had two younger sisters: Lisane, born in 1964, and Jeanine, born in 1967. His father, Gerard Basquiat, was born in Port-au-Prince, Haiti, and his mother, Matilde Basquiat, who was of Puerto Rican descent, was born in Brooklyn, New York.
Context: Basquiat sold his first painting in 1981, and by 1982, spurred by the Neo-Expressionist art boom, his work was in great demand. In 1985, he was featured on the cover of The New York Times Magazine in connection with an article on the newly exuberant international art market; this was unprecedented for an African-American artist, and for an artist so young. Since Basquiat's death in 1988, his market has developed steadily - in line with overall art market trends - with a dramatic peak in 2007 when, at the height of the art market boom, the global auction volume for his work was over $115 million. Brett Gorvy, deputy chairman of Christie's, is quoted describing Basquiat's market as "two-tiered. [...] The most coveted material is rare, generally dating from the best period, 1981-83."  In 2001 New York artist and con-artist Alfredo Martinez was charged by the Federal Bureau of Investigation with attempting to deceive two art dealers by selling them $185,000 worth of fake drawings put forth as being the work of Basquiat. The charges against Martinez, which landed him in Manhattan's Metropolitan Correction Center on June 19, 2002, involved an alleged scheme to sell fake Basquiat drawings, accompanied by forged certificates of authenticity.  Until 2002, the highest amount paid for an original work of Basquiat's was US$3,302,500, set on November 12, 1998, at Christie's. In 2002, Basquiat's Profit I (1982), a large piece measuring 86.5 by 157.5 inches (220 by 400 cm), was set for auction again at Christie's by drummer Lars Ulrich of the heavy metal band Metallica. It sold for US$5,509,500. The proceedings of the auction are documented in the film Some Kind of Monster.  In 2008, at another auction at Christie's, Ulrich sold a 1982 Basquiat piece, Untitled (Boxer), for US $13,522,500 to an anonymous telephone bidder. Another record price for a Basquiat painting was made in 2007, when an untitled Basquiat work from 1981 sold at Sotheby's in New York for US$14.6 million. In 2012, for the second year running, Basquiat was the most coveted contemporary (i.e. born after 1945) artist at auction, with EUR80 million in overall sales. That year, his Untitled (1981), a painting of a haloed, black-headed man with a bright red skeletal body, depicted amid the artist's signature scrawls, was sold by Robert Lehrman for $16.3 million, well above its $12 million high estimate. A similar untitled piece, also undertaken in 1981 and formerly owned by the Israel Museum, sold for PS12.92 million at Christie's London, setting a world auction record for Basquiat's work. In 2013, Basquiat's piece Dustheads sold for $48.8 million at Christie's. In 2016 an untitled piece sold at Christie's for $57.3 million to a Japanese businessman and collector, Yusaku Maezawa.  In 2017, Yusaku purchased Basquiat's Untitled (1982), a powerful depiction of a skull, at auction for a record-setting US$110,487,500--the most ever paid for an American artwork and the sixth most expensive artwork sold at an auction, surpassing Andy Warhol's "Silver Car Crash (Double Disaster)" which sold in 2013 for $105 million.
Question: What kind of art did he make?

Answer:
painting