In various collaborative works in this first gallery, the language of graffiti tagging merges with artistic signature. Key symbols belonging to each artist – Basquiat’s crown and Haring’s barking dog and crawling baby – can be found among the tags of a range of the artists’ contemporaries, including Fab 5 Freddy, Poet and Futura 2000.

Haring’s first drawings consisted of abstract forms, but he quickly developed a distinct artistic vocabulary consisting of characteristic symbols, including the baby, the human being and the dog. He ‘activated’ the silhouettes of these subjects by drawing radiant auras around them. Evident from the very beginning of his artistic practice was a fluidly executed technique that has been likened to Pablo Picasso: Haring’s work was often drawn in one continuous process, without taking breaks or stepping back until the composition was complete.

Basquiat’s self-portraiture is characterised by alternating or simultaneous displays of self-confidence, deep vulnerability and aggression. In most of his self-portraits, Basquiat did not attempt to represent his physical appearance in detail. Instead, he used mask-like stereotypes or symbols, reducing himself to a few brushstrokes of eyes, nose, mouth and dreadlocks. He took the same approach in his portraits of others, as seen in his 1980–81 depiction of Haring, Untitled (Keith Haring). Portraits of black men were largely missing in the European and American art Basquiat saw represented in museums or in books; in many cases, Basquiat saw his own portrait as standing for the portrait of all black men.

Haring’s work was influenced by the graffiti scene insofar as he drew and painted on almost any surface he came across, adapting his signature visual alphabet to fit unconventional surfaces. He gave his work to many friends and lovers throughout his career, often with handwritten dedications that demonstrate the generosity, exchange and interconnectedness between artists of the time.

Basquiat engaged with the subject of the street in a multilayered way. He painted and drew on everyday surfaces in his friends’ apartments (walls, refrigerators, radiators, pieces of clothing) but even more enthusiastically on objects he found on the street, such as discarded windows and doors, mirrors, cigar boxes, foam rubber and old boards. The artist placed his mark on everything that surrounded him: things he encountered by chance and things that literally stood in the way.

By the time Haring had his first solo exhibition, at the Tony Shafrazi Gallery in 1982, his alphabet of symbols was already fully developed. For this seminal exhibition, he created works on different materials ranging from paper and canvas to metal and large vinyl tarpaulins. Covering the walls of the Gallery almost completely, these works demonstrated the artist’s keen awareness of how pictures can function just like words, as carriers of meaning.

The defiant hero features prominently in Basquiat’s work, whether embodied in the figures of athletes and musicians or the allegorical representations of saints, warriors or the condemned. The portrayal of the singular black male reaches its pinnacle in Basquiat’s work from 1982, the year he began to depict his protagonists with considerable power and complexity. Untitled, 1982, demonstrates the dynamism and assertive nature of Basquiat’s free-form line, which he used to construct a standing male figure wearing a crown, his right arm raised.

Haring adopted a similarly multidisciplinary approach to his practice, creating paintings, sculptures, prints, text-based works, videos and photographs. He also ‘performed’ his drawings in public spaces, often in front of an audience. Basquiat, too, was active as a draughtsman, painter, performer, actor, poet, musician, fashion model and DJ.

Both artists were regular participants in the Downtown New York club scene, a place where creative experimentation with fashion, music, performance and art thrived. At nightclubs, including Paradise Garage and Club 57, people could be themselves, regardless of race, sexuality or gender. It was in these spaces that Haring and Basquiat met, shared ideas and collaborated with other creatives such as Warhol, fashion designer Vivienne Westwood, and performers Madonna and Grace Jones. For both artists, oscillating between different artistic disciplines came naturally and anticipated the interdisciplinary practices of many artists in the 1990s, as well as the diversity in creative careers that is commonplace today.

In contrast to Basquiat’s sometimes abrupt drawing rhythm, Haring let the pen or brush glide quickly across the picture support. The speed with which he drew his lines was honed during his subway drawing project. This rapid speed of execution was also instrumental to Haring’s seminal Fun Gallery exhibition in February 1983, for which he and a friend, artist LA II (Angel Ortiz), spray-painted the gallery walls with colourful pictures and tags. Haring then mounted works executed on leather and synthetic ‘skins’ over this dynamic surface, emphasising the immersive nature of his work.

Basquiat also had a formative exhibition at the Fun Gallery. In November 1982 he filled the gallery with works executed on unconventional supports. One of these works was A Panel of Experts, 1982, the canvas of which is stretched over wooden ‘crossbar’ supports bound together by twine. Swiss gallerist Bruno Bischofberger, who represented Basquiat from September 1982, noted, ‘I liked that show the best. The work was very rough, not easy, but likeable. It was subtle and not too chic’.

Haring was a prolific journal writer. His notebooks document both highly personal entries as well as his contemplations on politics, art and his experiences living as an openly gay man. Many of the entries feature sketches and drawings in which Haring explores different approaches to artistic questions. In the tradition of the concrete poets, he also experimented with text and even performed and documented some of his poetic forays.

The use of language was also a prominent part of Basquiat’s artistic practice. His notebooks reveal a voracious mind and include drawings, pictograms and symbols, as well as letters, poetry, lists and everyday jottings. In a sense, Basquiat’s entire oeuvre can be seen as an extended notebook.

The influence of Burroughs on Haring’s early text and collage works is direct, with Haring using Burroughs’s cut-up technique to manipulate headlines from newspapers, rearranging them to take a clear position against authority, racism and discrimination. Haring was also inspired by the artist Jenny Holzer, whose Truisms project of 1977–87 – for which she printed a range of aphorisms or widely held ‘truths’ and pasted them up on bus shelters, in subway stations and other public places – transformed the public domain during Haring’s first years in New York City.

Basquiat’s approach to collage was both sculptural and poetic. He drew his material from a vast range of sources and everyday objects around him, such as logos and slogans that dominated shopfronts and grocery store products, or the materials of his environment such as fence posts, doors, cast-off metal fixings. It is the appropriation of these coincidental and seemingly insignificant words and objects that gives his art its particular character. Basquiat copied and transformed found materials in works that pre-empt the copy-and-paste sampling of the internet and post-internet generations.

Basquiat’s motifs are quoted directly from his surroundings: the medical textbook Gray’s Anatomy, slogans and logos used in merchandising, or the cartoons and comic books he adored as a child. Repetition is used as a strategy for conveying meaning, with certain words and images frequently recurring in his notebooks and paintings. Haring once said Basquiat ‘wield[ed] his brush as a weapon’, struggling against exploitation, consumer society, repression, racism and genocide. He engaged with issues of identity in symbol-laden paintings that addressed political issues and criticised racism, social injustice and consumer capitalism.

Haring, on the other hand, created a new visual lexicon, essentially inventing his own alphabet to express his unique vision. His audiences – whether in the galleries or on the streets – learned to recognise key signifiers in his work: the crawling baby, the mushroom cloud, the dancing dog, the crucifix-wielding oppressor. Through these symbols, they understood his message, whether it was promoting gay rights, anti-nuclear protest or anti-authoritarianism. The contemporary rise of communication via emoticons and emoji has been profoundly influenced by Haring’s visual alphabet.

For his 1983 exhibition Into 1984, Haring created an immersive black light display in the gallery’s basement, where a DJ and breakdancers performed at the opening event. The strong influence of hip-hop and breakdance can also be seen in the imagery of many of the day-glo works on display here, in which figures execute moves inspired by breakdancing.

Haring’s paintings, drawings, sculptures and public works are filled with powerful messages of social justice and change. He was an activist and leading voice who fought for the individual and against its suppression by dictatorships, racism and capitalism. Several of the works by Haring in this room specifically address the subjects of the American civil rights movement and South African apartheid. Beyond the subjects of racism and corporate greed and the works included here, Haring engaged with a number of other political issues in his work, most prominently the AIDS epidemic and gay rights, to which he made an enduring contribution. Haring also addressed the threat of nuclear warfare, the impact of crack cocaine and social welfare. Although Haring never saw art as propaganda, he did use the mechanisms of propaganda and public space to distribute his art and ideas, insisting that art was for everybody.

Basquiat, too, took an uncompromising position as an artist, innovator and humanist. In his works he represents the power of the black male in his fight against oppression, throughout history and in 1980s contemporary culture. He also took a stand against police violence and racial persecution, issues that remain highly relevant today. Basquiat’s victorious figures are representations of strength and resistance, and often allude to African-American sporting heroes such as Jack Johnson (the first black heavyweight boxing world champion), Muhammad Ali and baseball player Hank Aaron.

With A Pile of Crowns for Jean-Michel Basquiat, 1988, Haring paid a final tribute to Basquiat after his friend’s death on 12 August 1988.

The subject matter in Haring’s works shifted markedly in 1985, when he began to rapidly lose many close friends and acquaintances to AIDS. In 1988, Haring learned of his own HIV diagnosis, and his battle with AIDS ended on 16 February 1990. In his last painting, Haring depicted a jubilant crowd ready to fight against oppression, suffering, death and downfall.