It begins once you put on the goggles and headphones. You wonder if you’re actually ready for this.

You’re floating.

Is it deep space?

Are you underwater? In a deep sea trench?

Then the music starts. Columns of color and shape begin to cascade in front of you, like liquid fireworks. Shapes that look like thick smoke or neon jellyfish float by to the left, right, and underneath. Sometimes they move straight through you. You crane your head up and down and realize you can see them fly by. You are immersed.

You listen closer to your headphones, which are playing a Miles Davis freak-funk soundscape, off of Bitches Brew. The shapes are reacting to (and predicting?) the music. You are lost, but you don’t care. It’s soothing and mind-expanding. (Keep in mind, your fearless writer wasn’t even on drugs when all of this was going on. In retrospect, this might have been a good time to start.)

After the first 15-minute “set,” you are now officially initiated into the cult of the OVC, or Outerspace Visual Communicator. You are also part of Boston Music History, at the end of a timeline that dates back more than four decades.

Bill Sebastian is the inventor of the OVC, and the man behind the curtain. His first, studio apartment-sized installment of the instrument was painstakingly constructed in the mid-1970s, before desktop computers even existed. An unfair but necessary quick description of the instrument might be: a keyboard that plays light instead of sound, projecting wild, multicolored patterns up on a huge screen above a stage.

Sebastian isn’t just a tech nerd, which is why this is such a unique story and experience. A multitasking keyboardist and computer whiz, he was performing and collaborating with one of Boston’s most underappreciated musical families in the late 1970s: the Johnson Brothers band (not to be confused with the Brothers Johnson). Sebastian brought legendary jazz bandleader Sun Ra into the OVC’s orbit in the late ’70s, allowing the unique instrument to be used at performances from 1978 to 1980, locally at the Modern Theater and at Mass College of Art.

While he has had various diversions to pay the mortgage since that time, Sebastian has had only one true obsession in his life—the OVC. After several years of work by almost a dozen programmers, a new, software-based version is now ready to have its moment. And a few lucky Bostonians can join in the fun by securing a seat in a weekend showing at the maestro’s loft near Downtown Crossing until the end of May.

As was the case back in the late ’70s, Sebastian is the sole controller of this instrument of light. His hands, connected to sensors, dart about as the performance happens. His shoeless feet control colors on a series of foot pedals. To try and really understand everything he is doing wouldn’t necessarily enhance the experience. Just know that each performance is unique, and he is the reason for that.

“This visual world is being created live, by a visual musician: me,” Sebastian told DigBoston. “Under real-time control, the patterns and colors become alive in a strange and magical way unlike anything in Virtual Reality. Sun Ra said that other worlds spoke through his music, which is why we called the original instrument the Outerspace Visual Communicator. The OVC-3D is not a VR generator, but rather is a communication device, and my goal as an artist is to get out of the way and let these worlds speak for themselves.

“I have been bored by reality for a long time. We are sending out an invitation to people who want to go someplace different and are willing to fly to destinations unknown.”

Learn more about the OVC-3D and Bill Sebastian at visualmusicsystems.com/blog.html. Visiting hours are at 80 Summer St. in Boston on Fridays, Saturdays, and Sundays. Reservations required.