ON A WILD slope of land in Cape Breton Island, Nova Scotia, stands an old wooden house, its back to the forest, its face to the sea. The house belongs to Joan Jonas, the 86-year-old American artist whose mix of performance, video, painting, drawing, sculpture, and installation shaped the aesthetic vernacular of a generation of artists. She is nearly always described as “pioneering.” Here, in the house where she has summered since 1974, she is relaxed, if hard at work. The sun is on her face. A big Museum of Modern Art survey show will open in New York next year. She’s preparing.

The house is filled with objects that glow with mute incandescence: a painted animal mask (a seal? A wolf?), a village of miniature houses, a carved puffin on a rock, a slice of mirror, a pile of stones. In the background, the soft expanse of the sea. Each item is from Cape Breton, collected by Jonas, and a keen observer of her work will recognize them from her videos. Indeed, collected, the objects tell the story of Jonas’ oeuvre: mask, mirror, animal, sea.

Masks. In 1970, Jonas started using masks after she went to Japan and saw Noh theater. They appear in nearly every one of her works: scary masks, doll masks, animal masks in papier-mâche. Masks from Canada and masks from Central America. At times, their presence is menacing, at others benign. In her first piece of video art, “Organic Honey’s Visual Telepathy” (1972), Jonas wears a doll-woman mask, blank and banal, which she bought at an erotic store in New York City’s Times Square. She dons a headdress and dances. “I’ve always been interested in how you can be disguised,” she says. “In the work I was doing, I wanted to be somebody else, not Joan Jonas. I didn’t want to play myself. So I started using masks. They transform you.”

Mirrors. The only context in which we see Jonas’ own face in “Organic Honey’s Visual Telepathy” is in a mirror, in which she grimaces, and later hammers with her fist. She uses mirrors to multiply perspectives and to draw the audience into the world she has created. In “Mirror Piece” (1969), female performers move slowly and deliberately, carrying 17 oblong mirrors that always face the audience. In “Mirror Check” (1970), she examines every inch of her own naked body with a handheld mirror. In “Waltz” (2003), she holds mirrors out to the landscape of Cape Breton — to the wind, to the stones, and to the squinting face of her dog, Zina.

Animals. “I think animals should be represented as part of our world,” Jonas says. “They should be visible; they should be recognized as beings.” In Jonas’ world, animals seem to stand somewhere between this world and another, emissaries from beyond. In 2015, she represented the United States at the 56th Venice Biennale with the installation “They Come to Us without a Word,” meant to evoke everything in nature we stand to lose. A series of rooms — mirrors, bees, fish, wind, homeroom — contain videos, mostly shot in Cape Breton, alongside other visual elements: her ink drawings of fish and bees, rippled mirrors crafted in Murano glass, an enormous chandelier, tree trunks tied with twine. In an audio recording, Jonas and others read fragments of Cape Breton ghost stories aloud.

The installation was inspired by the novel “Under the Glacier,” by the Nobel Prize–winning Icelandic author Halldór Laxness. In it, a bishop sends a young man to a small village to investigate strange rumors that the village pastor has abandoned his duties, closed the church, and does not bury the dead. The bishop does not want the young man to take any action, nor to judge, but simply report what he finds there. It is the young man’s innocence that recommends him; someone wiser might be more apt to meddle. “His task,” writes Susan Sontag in her introduction to the novel, “is to be a mirror.”

“Under the Glacier” is a strange book, humorous and enigmatic, full of riddle and mystery. It describes a landscape of cliff and coast, tree and glacier, that dazzles and mystifies its inhabitants in turn. It bears, in fact, an uncanny resemblance to the ineffable mix of qualities that constitute a Joan Jonas work: wry humor, natural majesty, myths, and fables. Sontag’s description of the protagonist could easily describe Jonas: “Skeptical, recalcitrant, astonished, ready to marvel.”

The sea. Lately, Jonas has turned toward the sea. In 2019, she was commissioned to create a piece to mark the inauguration of the exhibition center Ocean Space in Venice, Italy, which became “Moving Off the Land II.” The vast number of elements that comprise the installation includes music, ambient recordings, drawings, footage of sea animals in aquariums, video art featuring Jonas and children in white reciting poetry, and mirrors that reflect the audience. Her interest in the ocean, beyond the ecological, is mythical. In a vocal recording, she says, “How does myth arise? We all come from the sea. And we have memories of it.” But there’s also a trace of the personal. “The ocean is right there in front of my house,” she reflects. “Yes, it is.”