It starts with long drawn-out notes forming a simple melody. The sound of the alto saxophone is warm and reedy. At first, you might wonder, where is this going? But then, with the help of a loop pedal, the saxophone harmonizes with itself, and a piano joins in with low rumbling notes.

This improvisation between saxophonist Ken Field and pianist John Thomas is part of the first episode of “Music Without Borders,” a virtual series presented by the Provincetown Theater in which Thomas plays world music and original compositions with special guests each week. Field returns for episode six on Sunday, Feb. 28.

For the last 20 years or so, Field has been spending part of his winters and all of his summers in Truro, and the rest of the year in Cambridge. “My original connection was actually doing an amazing gig at a now defunct room on Shank Painter in Provincetown with a ’70s band called Crown Electric Company,” he says. Now, he plays locally with Chandler Travis, Zoë Lewis, and Mark van Bork.

Growing up in New Jersey, Field started on clarinet when he was 10 years old. Though he played mostly band music, he listened omnivorously to all types of jazz and pop on the radio. “One thing I credit that period with is giving me a really solid sense of time, of rhythm,” he says.

As an undergraduate studying computer science, he knocked out his front tooth in a freak accident and switched to flute, then picked up the alto sax — both were easier on his new smile. He eventually decided to pursue music full-time instead of working with computers, and studied with Joe Viola at Berklee School of Music.

Field first tried improvising as an undergraduate. He was working at a coffee shop where a blues band performed and would play along softly on his flute. “I was kind of jamming with them behind the counter, but no one could hear me,” he says.

He started layering his performances at Berklee. He’d be recording solos for other people’s songs, and, after a couple of takes, ask to hear the takes played together, simultaneously. “It always reminded me of looking at yourself in a dressing room mirror, where you see multiple images of yourself,” he says.

He found the process useful when he did the music for the animated shorts his late wife, artist Karen Aqua, created for Sesame Street. “We didn’t have much of a budget, so I would layer myself, on saxophone, in the studio,” Field says.

His first solo album, Subterranea, was recorded in New Mexico — where Aqua was doing a residency — in an underground space with “amazing acoustics,” using a rented multi-track tape recorder.

He wrote layered saxophone music for Bridgman/Packer Dance in New York, performing one track live; the dancers performed with video projections of themselves. While touring in Budapest, the company needed music during a set change. “There wasn’t a budget to bring any other musicians, and I was very nervous about doing solo saxophone,” Field says. That’s when he started using a loop pedal.

“I’m using the looper in a slightly different way than a lot of people,” he says. Instead of recording a groove, adding a bass line, and overlaying a melody, Field’s method is “totally rubato,” he says, with more of an ambient sound. He recently recorded a whole album with loop pedal, Transmitter, coming out April 2.

What goes into that first track? “I would like to say that I’m not thinking at all, and it’s just streaming out of my emotional state,” Field says, but there are considerations. The melodic phrase repeats, so it must be interesting, sparse, and tonally simple — no complicated chord changes.

“There are pluses and minuses” to performing with yourself, says Field. It may be safe in a pandemic, but feeding off another person is intrinsic to improvisation. “Doing it alone, I can do exactly what I want,” he says, but, he admits, “I get in ruts.”

Covid has been tough on musicians and audiences, yet Field remains optimistic. He performed outdoors last summer and has been recording tracks from his home in Truro. He’s been memorizing Bach’s first cello suite transcribed for saxophone. “I think the cello and alto sax have a lot in common,” says Field.

And, for the last 10 years, he’s hosted the radio show The New Edge on WNBR and WOMR, dedicated to creative instrumental music, including contemporary classical and electronica.

“Music Without Borders” has been a creative boon. “I have so much respect not only for John’s musicianship and his varied musical interests but also how much he gives back to the community,” Field says. Their upcoming streamed performance will be an arrangement of the hymn “Abide With Me.”

“I’ve always been attracted to music that’s a little different,” says Field. “If you try something new, you don’t know if it’s going to work. That’s the definition of experimental. It’s an experiment.”

In the Loop

The event: Ken Field joins John Thomas for an episode of the Provincetown Theater’s virtual series “Music Without Borders”

The time: Sunday, Feb. 28, at 7 p.m.

The place: Streaming at provincetowntheater.org

The cost: Free; $15 suggested donation