Today is the 35th anniversary of the assassination of John Lennon. But instead of dwelling on that tragedy, let’s take a look at Lennon’s wife and partner, conceptual artist Yoko Ono.

• In 1966, Ono mounted a show in the Indica Gallery in London. John Lennon opted to attend, and he got to get in early—VIPs often get to go to art shows before the general public, ostensibly because gallery owners hope they’re more likely to buy something. This was explained to Ono…who had never heard of John Lennon or his band, the Beatles.

• One of the exhibits was an apple, on sale for £200. There was nothing special about this apple, it was just sitting on a stand, and the buyer was paying for the right to watch it decompose. Lennon saw the “humor” in it, but art historians say this is an iconic moment in art. Ono didn’t create the art but curated it, and made the patron a part of the artistic experience, no longer an outsider.

• Another example of Ono’s pioneering of what we now call “performance art” and “experimental art.” In 1964’s Cut Piece, she sat in a chair and allowed gallery visitors to snip off pieces of her clothing with a large pair of scissors.

• Another ‘60s piece: a ladder led to a painting hung on the ceiling. From the ground, it looked like a black canvas, but upon climbing the ladder, patrons found a spyglass connected to it with a chain. Using the spyglass, they looked at the poem, where in tiny letters was the word “yes.”

• In the late ‘60s, Ono and Lennon (only partially jokingly) created bagism. It advocated for people to cover their bodies in cloth bags so as to negate any sort of preconceived notion from others based on appearance, with special attention to race, gender, body type, or age.

• Ono and Lennon once sent acorns to the heads of state in 50 countries. The leaders were asked to plant the acorns as a symbol of, and commitment to, world peace.

• When they first met, Ono told Lennon about a dream project called a “light house,” a theoretical “structure” made only of light directed through prisms. Lennon commissioned her to build one for him, but she had no idea how to do it. But in 2007, Imagine Peace Tower opened in Reykjavik, Iceland. Light projects from out of a wishing well, inscribed with the words “Imagine Peace” in two dozen languages. It creates a structure of light. The tower goes up every October 9 (Lennon’s birthday) and shuts down every December 8 (the anniversary of Lennon’s death).