After San Marco, the most famous church in Venice is Santa Maria Gloriosa dei Frari. The vast 15th-century building, its wide, high central nave and chapels lined with important monuments, has been described as a Pantheon of the glories of La Serenissima. There's a lot to look at, but the most spectacular of the Frari's many riches is the enormous painting above the high altar, Titian's "Assumption of the Virgin" (1516-18). Recent studies have revealed that the great panel, painted when the ambitious young virtuoso was 28 and intended to assert his mastery, is apparently all by his own hand, made without the aid of assistants. When this magnificent work was first unveiled, it announced a new conception of what an altarpiece could be, both in the grandeur of its scale and the simplicity and unity of its composition, and successfully staked Titian's claim to being the most important painter in Venice.
At nearly 23 feet tall, in a frame like a triumphal arch (probably designed by the artist), the "Assumption of the Virgin" dominates the space above the altar, against a haze of light spilling from the lancet windows of the apse behind it. It's an astonishing painting, first capturing our attention with its bold economy. Titian translated his dramatic motif into a nearly abstract, simple structure that declares itself clearly from a distance, making the powerful image of Mary's ascent to heaven intelligible to worshipers the length of the nave.
The painting is divided into three rather widely separated zones of activity: First, there's a horizontal mass of awe-struck, gesticulating apostles who fill the bottom third of the immense wood panel, tightly packed together below a band of pale blue sky. Next, there's a descending arc with a swaying vertical element in the center: the Virgin, arms raised and balanced on a cloud populated by a throng of putti and a few slightly older angels, as she floats upward from the painting's midpoint into a golden dome of heavenly light. Above her, in a narrow band seen from below, God the Father, flanked by a putto and an angel, swoops in at a slight angle that expands the space, framed by a curving band of closely pressed putti, like a smaller, more distant version of Mary's arc of escorts, all golden orange in the celestial light.
The more time we spend with the painting, the more brilliant and unexpected Titian's staging of the miraculous event appears to be. As we admire the generosity and amplitude of his forms, the simultaneous delicacy and boldness of the modeling, and the rhythmic folds of the drapery, we also note how subtly he played with our expectations of symmetry and marvel at how he created big, eloquent gestures across his huge image both to engage the eyes of even distant viewers and carry the narrative.
Each apostle reacts differently to the vision. One shades his eyes. One kneels in prayer. One raises clasped hands like a supplicant. The figure closest to us turns his back and reaches up, as if longing to embrace the Virgin before she vanishes. All of them gaze upward, as we do, at the rising figure of the Virgin in the implied golden dome of light. In her red robe, she forms the apex of a tall, narrow, slightly asymmetrical triangle. The triangle is visually supported by the apostle with his back to us, one bare arm extended, and his opposite number, who faces us, one arm bent and covered by an artfully draped sleeve. Like Mary, this crucial pair wear red. So does God the Father; a glimpse of his scarlet robe pulls our eye to the top of the panel, so that we metaphorically recapitulate Mary's journey heavenward as we explore the painting. But variations in each of the reds slow us down, making us consider each element individually.
The Virgin's mantle, blown to one side but prudently knotted for her upward voyage, forms a sweeping dark-blue arc that restates, at smaller scale and with new animation, the curving band of cloud and putti. Our perceptions of the different sizes and slightly altered orientation of the two arcs, like the differences in the amounts and types of the color red, as we move through the painting, intensify the sense of ascension. The play of reds, greens and blues—and even some purple—against the radiant ground further heightens the illusion of motion. (It has been suggested that Titian adopted a brighter palette than usual to counteract the sidelight from the apse windows.)
Thanks to Save Venice Inc., the American charitable organization that for decades has been preserving the city's gems, the "Assumption of the Virgin" has recently been treated to dust removal—the horizontal inflections of the wooden panel catch grime—and careful study to determine what might need to be done since it last received conservation treatment in 1972. Generally, the nearly 500-year-old painting is in good condition, but small test patches to remove discolored varnish have revealed its original splendor. Save Venice is poised to begin a campaign to raise funds for conservation, but work can't start until an extraordinary problem is solved. In the 1930s an organ was installed behind the painting, and in the 1970s the pipes were attached to the panel. (Don't even think about what the vibrations are doing.) Negotiations about relocating the instrument have been initiated. Let's hope they are successful so that Titian's Santa Maria Gloriosa can return to her full glory.
—Ms. Wilkin is a critic and independent curator.