Why abstract art? The question is not rhetorical, especially as a point of entry into the visionary work of Jack Whitten, whose career spanned six decades before he died in 2018. One possible answer: the need to say what cannot be said according to the usual rules—rules for perspective, light, scale, and all the rest, but also, and maybe most importantly, rules for representing the world in a way that the world has already recognized. What looks real, what is real, may not be the same for you as it is for me. That makes it vitally important for artists to paint, sculpt, or draw the world as they see it, regardless of the rules. And that is particularly true when the rules—inside the world of art schools, galleries, and museums and, most especially, outside it—constitute the very evil that makes their work necessary.

That was certainly true for Whitten, the African American son of a coal miner and a seamstress, born in 1939 and raised in segregated Bessemer, Alabama. Here is how segregated: Whitten and other Black students were prohibited from visiting art museums, so they toured the area’s coal mines and steel mills instead. The first member of his family to attend college, Whitten became a premed student at Alabama’s Tuskegee Institute before shifting his focus in 1959—ironically, given the restrictions placed on him during boyhood—to art. He studied at Southern University in Baton Rouge, Louisiana, where, after becoming a follower of Martin Luther King Jr., Whitten participated in civil-rights demonstrations. But he didn’t stay in the South: the violent reactions of local segregationists and the desire to avoid becoming violent himself led Whitten to New York City. He received a scholarship at Cooper Union, immersed himself in all kinds of art, from literature to dance to jazz, and became enamored of the work of the Abstract Expressionists.

The new Whitten show at the Museum of Modern Art, on view through August 2, is the artist’s largest and first complete retrospective, including works spanning over half a century. As the earliest works in the exhibition make clear, Whitten embraced abstraction from the beginning. Five black-and-white works from 1964, Christ, Head VII, Head IV Lynching, Psychic Eclipse, and Head I, all made with acrylic paint on canvas, have a ghostly quality. Head I is emblematic of many of Whitten’s early works, with its hints of the “real” among the abstract: areas resembling teeth appear among pockets of darkness and murkiness, that small touch of realism heightening the work’s ominous feel. Another example is NY Battle Ground (1967). In bold color rather than black and white, this painting is nonetheless similar to Head I in its depiction of recognizable or near-recognizable objects amid abstraction; here, what look to be the eye and beak of a bird, along with seemingly airborne objects vaguely resembling insects, appear in the midst of chaos, including what may be dripping blood. The painting is Whitten’s response to the violence and upheaval of the era, associated with both the war in Vietnam and unrest at home; a viewer may not know how to respond to it—which may be the point. Equally colorful and chaotic is King’s Garden (1968), painted in the year of the civil-rights leader’s assassination and showing faces among the unruly brushwork. There is almost too much going on to take in—surely how many felt during the late 1960s.

If the segregated world of Whitten’s youth represented the very worst kind of control, then his eventual response was not to impose control of his own, but, generously, to forgo it altogether. That may account for the next phase of his career. The exhibition quotes the artist as saying that “1970 was the turning point” in his work. “The studio became a laboratory designed to experiment with acrylic paint”—experiments that came in time for his solo show at the Whitney museum in New York, a rare opportunity for Black artists in that era. Getting rid of his brushes, Whitten invented devices for creating his works on canvas, including “the Developer,” a twelve-foot-long wooden rake. He used the Developer to pull layers of  paint across the canvas in one quick motion, with results designed to be unpredictable—a process he called “gambling.” There’s real freedom in such risk-taking and unpredictability. The results are abstract works that are, in some ways, arguably more “real” than representational work, in that their creation involves an element missing from most painting but always present in the world beyond the canvas: chance.

One such work is Mirsinaki Blue (1974). The painting was inspired by Whitten’s first visit to Crete, in 1969 (he would return to Greece in summers throughout the rest of his life). Referring to the Mediterranean Sea, he said that the trip included his “first time in blue water with no horizon.” Adding polymer gels to acrylic paint and spreading the mixture across the canvas with the Developer, Whitten created a blue-and-brown field with a stunning resemblance to the surface of water. The brown portions look like objects that are either in the water or reflected on its surface; a couple of those areas even look like fish. Fitting the Developer with a metal blade, Whitten created Siberian Salt Grinder (1974). Abstract shapes alternate with black areas that are surrounded by color and resemble a vertical arrangement of mountain ranges at sunset; the streaks of color made by the Developer give a sense of movement, even as the painting as a whole evokes stillness. The work is dark, befitting the title; yet it is calm. Also created with the Developer, Black Table Setting (Homage to Duke Ellington) (1974) captures something of the elegance in the music of the celebrated composer, pianist, and bandleader. Its colors—mostly black, brown, and beige, as in the title of one of Ellington’s most famous works—stretch horizontally, seeming to extend beyond either side of the canvas, suggesting timelessness, infinity, eternity; that, in turn, suggests the way the music lives beyond the man, who died that year. Whitten’s other tributes to Black heroes would follow in the years ahead, created with still more innovative techniques.

The 1980s saw Whitten experiment with objects picked up on the sidewalks of New York. Making plaster molds of the ridged bottom of bottles and covering them with paint, squeezing paint through the holes of steel grates or manhole covers straight onto the canvas, and making impressions using other found objects, the artist created works he called “skins.” One such work is Norman Lewis Triptych I (1985), made with the use of a gridded screen and named in honor of the famous Black Abstract Expressionist who was Whitten’s friend and mentor.  Another “skin” is Bessemer Dreamer (1986), a large painting—in white, black, tan, and light blue—that vaguely resembles a map, though not of any place a GPS could help you reach; the landscape represented seems internal, though it is also literally from the street. Still another is Spiral: A Dedication to R. Bearden (1988), named for the African American artist Romare Bearden, whom Whitten also considered a mentor. A nod to Bearden’s signature collage style, with grate patterns mixed in among other, harder-to-identify shapes of various colors, the work brings to mind a junkyard, an unassuming place where treasure can be found if one is of a mind to look.

If Whitten’s works made with the Developer involved relinquishing control, then a technique he developed two decades later might be said to embrace it. Both approaches respond to the control of the segregated world from which Whitten came. One is about escaping that world and its rigidity, while the other aims at taking that world apart, then remaking it to suit the artist’s own purposes. (“My paintings are designed as weapons,” Whitten said. “Their object is to penetrate and destroy the Western aesthetic.”) Among his purposes were celebrations of Black artists of various genres. In the 1990s, Whitten began his practice of cutting sheets of congealed acrylic paint into thousands of mostly square or rectangular pieces, then assembling them into large, powerful mosaics.

The Messenger (for Art Blakey) (1990), which gives the exhibition its name—and is one of the first works viewers encounter—is an homage to the music great, whose superhuman ferocity on the drums gave Blakey’s group, The Jazz Messengers, its unique sound. Whitten’s work alternates black tiles in a gridlike pattern with white tiles so small and concentrated that, together, they resemble galaxies. Homecoming: For Miles (1992) is made up of black, white, and gray tiles of more uniform size, the gray creating a muted effect, calling to mind the contemplative, aching solos from Miles Davis’s frequently muted trumpet. Flying High for Betty Carter (1998) is named for the great jazz singer Whitten heard perform in the East Village. The artist called the work “a B-52 Stratofortress Bomber piloted by General Betty Carter flying at 50,000 feet”—hence what looks like an aerial view of mostly white areas with some red-orange patches and one imposing, right-leaning, mostly black formation, mysterious and powerful in equal measure. The shadow of a B-52? The segregated area of a city? Or the expression of an otherwise inexpressible idea, one that cannot be conveyed in conventional terms but may reach us nonetheless, in a way we can’t articulate? That power and mystery, otherwise inexpressible, are at work in other large-scale mosaic works Whitten completed in the last decade of his life: the black-and-white Atopolis: For Édouard Glissant (2014) and the multicolored Quantum Wall, VIII (For Arshile Gorky, My First Love In Painting) (2017).

Those qualities are on display, too, in Whitten’s sculpture, which viewers encounter deep into the exhibition, though some of the works are from early in his career. John Lennon Altarpiece, from 1968, is made of wood and metal—a great many pieces of metal, from nails to screws to hinges, packed together so tightly that nothing is visible between them. Inspired largely by African sculpture, which Whitten called “the ‘DNA’ of all art,” the work suggests a center toward which all is irresistibly drawn, as in a black hole, or, perhaps, a source from which all springs—or both. It is a work that, like Whitten’s Developer paintings or mosaics, speaks powerfully in a heretofore unknown language. It recalls a line from the novelist Ralph Ellison, the subject of a 1994 work by Whitten: “Who knows but that, on the lower frequencies, I speak for you?”