Ms. Ono, a spry 74, was discussing—rather optimistically—the current state of politics. “One side of what’s happening to America is really sad,” she said. “But actually there are many, many people standing up now to really say that we want world peace …. The opposition is voicing—very loudly—and I think that we should be proud of that.”

Wearing a tilted fedora and bejeweled tinted glasses that hovered near the tip of her nose, Ms. Ono was bathed in a saffron fog from a wall full of vanity lights—better than Botox, if you ask us. “I think that our globe is definitely going to survive and we’re going to make it survive,” she said, pausing to take a few slow breaths. “I really believe in the survival instinct of the human race, and I’m sure that we’re going to—in the last moment, in the last minute—we’re going to stand up and do it!” You go, sister girlfriend!

Ms. Ono’s most recent work was called IMAGINE PEACE—a Christo-like multimedia extravaganza that involved distributing posters around Washington, D.C., and planting 10 “wish trees”—cherry trees on whose branches passers-by are encouraged to tie pieces of paper inscribed with their innermost yearnings. Next up: Imagine Peace Tower in Iceland, featuring a column that will stand some 80 feet tall, engraved with the lyrics of her late husband John Lennon’s famous song, “Imagine.”

She also recently collaborated with contemporary artists—the Flaming Lips, Felix Da Housecat, D.J. Spooky and the Polyphonic Spree, among others—on the albums Yes I’m a Witch and Open Your Box, which contain remixes of her old songs. “These are, as you know, the stars of the indie music, so I’m really honored that they wanted to do it,” Ms. Ono said, adding with a sheepish shrug: “Making art, making music—for me it’s almost like life itself. It’s like breathing, so I just have to keep on doing.”

Although there is no imminent project with her son, musician Sean Ono Lennon, 31. “We’re just kind of moving parallel to each other at this point,” she whispered.