Ryuichi Sakamoto is in Tokyo for the summertime rainy season. A New York resident for over 30 years, the Oscar-winning composer has been in Japan since last November — not because of the pandemic, but because of a diagnosis of rectal cancer, discovered just after he went into remission after several years of treatment for throat cancer.Despite his health problems, Sakamoto has been as prolific as ever, participating in concerts, exhibitions and most recently an opera, “Time,” which premiered last month at the Holland Festival.“Time” is part of Sakamoto’s ongoing exploration of “asynchronism,” music arranged outside traditional time structures. Introduced on his 2017 album “async,” the concept was conceived as he recovered from his first bout with cancer — an experience that he has said newly honed his ear to the beauty of everyday sounds, both natural and man-made, sun showers and singing bowls.Without conductor or tempo markings, “Time” is a “Mugen Noh,” a subset of Noh theater based on dreams. Created in collaboration with the visual artist Shiro Takatani, this dreamscape unfolds on a stage filled with water and a screen displaying weather systems, cities and empty space.Crossing and recrossing the stage with her sho, an ancient Japanese wind instrument, Mayumi Miyata represents nature. The dancer and actor Min Tanaka is a frail symbol of humankind, struggling to build a road across the water. Summoning visions of rising sea levels, “Time” — like our new century — presents a premonition that also feels like a memory: At the end of time, we all return to the same sea.Sakamoto spoke about the piece on a recent video call. These are edited excerpts from the conversation.At what point in the production of “Time” did you find out your cancer had returned?I worked on “Time” for four years after “async,” and I was diagnosed with rectal cancer last year. It’s a long treatment. I’m in the middle right now, and will go back to the hospital for surgery in the fall. It’s been a year since I left New York; I don’t know when I can come back.Were you originally planning to perform in the opera?I was thinking of making an original instrument for it. I still have this idea for the future.I was using the word opera in the beginning, but I’ve stopped using it. It’s a combination of installation and performance — a theater piece.It seems quite deeply connected to “async.”The conceptual idea behind “async” was my doubt about synchronization, and that led me to think about time itself. If you know my work from the past, I zigzag. But the things I got from making “async” were so huge that I didn’t want to lose them. I really wanted to develop them. The album was so spatial, like music for an installation, so the development would be an installation of performers together. That was the original idea for “Time.”“Time” is a Mugen Noh — it has no tempo — so it does seem like the perfect landscape to explore these ideas.Time is so natural to our society that we don’t doubt it. But because I’m a musician, I deal with time all the time. When we compose, we have to think about how to manipulate sounds in time.There are no instruments onstage, except the sho.Only the sho, which I have been fascinated by since I was a university student. I disliked all other Japanese traditional music, and even other traditions, like kado [flower arrangement] or sado [tea ceremony]. I hated it all, except gagaku [court music], which is like aliens’ music to me.Miyata, who represents nature, crosses the water so easily, while Tanaka — “mankind” — is so feeble.Woman and sho, they represent nature. Tanaka wants to create a straight road in the water — in time — to get the other side, but he fails. He goes insane and dies in the water at the end.What is humanity trying to reach at the end of the road?That’s mankind’s nature. A bit like Sisyphus: just a natural passion to make a road, to conquer nature.The road-building scenes interrupt a series of stories: a dream from the work of the writer Natsume Soseki; a traditional Noh play; the butterfly dream from the text Zhuangzi. How did you choose these?In our dreams, all properties of time are destroyed. In the Noh story “Kantan,” a man is looking for enlightenment and takes a nap. It just takes five minutes, but in his dream, 50 years has passed. Which is reality? The five minutes or the 50 years? And then in the butterfly dream, we have the philosopher Zhuang Zhou. Does the butterfly dream he is Zhuang Zhou, or does Zhuang Zhou dream he is a butterfly? We cannot tell.By freeing time musically, do you feel it slow down?The theme of “Time” is to insist that time doesn’t exist, not that it’s passing slowly. Watching the streaming premiere, I sensed that one hour ago was just a minute ago, or some moments were repeated. At least I could feel another kind of time.You’ve also been painting on ceramic pieces (“2020S”), using found objects, and making installations (“Is Your Time”), and you currently have a large retrospective in Beijing, with a lot of visual work. What provoked this turn toward the visual arts?Maybe the big moment was the opera I composed in 1999, “Life.” It included visual images, moving images and some texts — all those visual elements were the main characters of that opera.And that was your first collaboration with Takatani?Yes, and the next thing we did was to deconstruct “Life.” We deconstructed all the visual images, and the sound, too, to create an installation in 2007. That was a big moment.I guess you’ve always worked in the visual arts — you’ve worked so closely with filmmakers on soundtracks.Strange, you know, I didn’t think about films. Films are more narrative, more linear. Unfortunately, a linear structure is in time; it has a beginning, middle and end. I don’t want to go back to that. This is why I’m fascinated by installation. Installation doesn’t have to have a beginning or end. The best installation, I think, is just listening to rain.And you have a tremendous rainstorm at the end of “Time,” followed by the crashing of a wave in slow motion. What sea were you thinking of?Man wants to conquer nature — the water — but he must fail, so he must die by water. I needed a huge flood, maybe a tsunami, to represent the violent power of water. Also, almost all ethnic groups have some memories of a big flood. Maybe we all have some deep memory about surviving a flood.I think a lot of people will wonder if this opera is primarily about climate change.Climate change is the most vivid conflict between mankind and nature so of course it is included. But it’s not the main focus. I wanted to create a myth about mankind and nature.It’s very similar to Soseki’s dream, in which a woman returns as a flower growing from her own grave. I’ve read a few interpretations. To some it represents Soseki’s struggle with the modern world.It is my belief about reincarnation. Because she promises she will be back in 100 years, and she’s back as a flower. You know, I always wanted to be buried in the ground, so that my body would become the nutrition of other living things. And in Soseki’s story, the woman becomes a flower. It’s so beautiful.I love your interpretation.Very romantic, no?