Singer-actor James Jackson Jr. doesn’t take well to other people’s preconceptions about what he should and shouldn’t be doing. He’s turned defying expectations into something of a trademark in his cabaret career.

“Anything I’ve ever been told not to sing, that’s where I live,” says Jackson. “That is my wheelhouse.”

Early in his career, people said he was not the right type and didn’t have the right voice to sing certain songs that he loved — hits by women stars like Aretha Franklin, Tori Amos, Joni Mitchell, Ani DiFranco, the Indigo Girls, and Joan Armatrading. He didn’t take their advice.

“In the beginning, I was a little terrified to sing songs I was drawn to,” says Jackson. “But it’s so freeing. It changed how I went into cabaret spaces because I was so comfortable with the songs.”

His mother, a piano prodigy, exposed him at an early age to all kinds of music — from Nina Simone to Beethoven. That helped him, he says, to resist people trying to limit his choices.

“I can sing Aretha Franklin and you’ll like it,” he says with a laugh. “I like changing someone’s mind in the middle of a song.”

Jackson says he’s seen students being told by other teachers to stay in their lane — to stick with certain types of songs based on how they look and the style of their voices. He tells them to push back and not let themselves be pigeonholed.

“It’s just singing,” he says. “There shouldn’t be rules about that.”

That principle will be clear at the shows he’s bringing back to Provincetown on Oct. 11 and 12 at Post Office Cabaret. He’s delighted that the shows will include his longtime accompanist and music director Elliott Roth, allowing Jackson to perform songs he hasn’t performed here before. Noting how he’s learned the value of collaboration over the years, Jackson says, “I do one-man shows, and it takes probably 20 people to get that happening for one night. You cannot do anything alone.”

Collaboration and bucking convention were also behind Jackson’s musical-theater success in A Strange Loop. His theater credits include New York, regional, and national touring companies, plus, for 13 years, helping his friend Michael R. Jackson and other actors develop A Strange Loop. The creators and ensemble won an Obie Award for 2020’s off-Broadway production, which also won a Pulitzer Prize. In 2022, the musical moved to Broadway — James Jackson’s debut there — earning 11 Tony Award nominations and winning two, including Best Musical.

The plot of A Strange Loop has been described as “a Black queer man writing a musical about a Black queer man writing a musical.” Some people thought it was a bad idea.

“We were told from the minute we performed it that ‘It’s too Black, it’s too gay, it’s too all of these things that you are,’ ” Jackson says. “And that drove how we continued to work on it.”

Pushing back is also part of Jackson’s role as an educator. An adjunct theater arts professor at Manhattanville College, he uses A Strange Loop’s success to encourage arts students to persist when they face obstacles. “If someone sees I can do something, and it makes them think that they can, I’m down for it,” he says.

Jackson’s most high-profile successes — including 2023’s off-Broadway White Girl in Danger and co-creating the podcast Five Questions with James & Jam — have happened in the five years he’s become known as a frequent Provincetown entertainer. Jackson grew up in Randolph and has been coming to Provincetown since childhood. Performing in town, though, started after drag queen Anita Cocktail introduced him to the owners of the Post Office Cabaret and Tin Pan Alley.

Jackson brought a solo show to the Provincetown Theater last year, and he performed in last month’s benefit for a first-in-the-nation professorship in sexual and reproductive justice named for Provincetown’s Byllye Avery.

Many non-Cape friends have said they don’t feel comfortable as Black queer people in Provincetown, Jackson says, but he’s never had that experience. In recent years, he’s joined efforts to get the town better known as welcoming to visitors and performers of color.

Jackson has helped plan the town’s Juneteenth celebrations, this year creating a sold-out cabaret show about Black performers who’ve played here. Research produced results that surprised him, encouraging Jackson to advocate for more attention to the town’s Black arts history.

He mentions Black painters and sculptors but also the Fisk Jubilee Singers, a Tennessee university chorus known for slave songs that played at Provincetown Town Hall in 1893. Singers ranging from Nina Simone to Richie Havens performed here, Jackson notes, with the Atlantic House hosting Eartha Kitt, Billie Holiday, and Ella Fitzgerald during one month in 1955.

Mentioning the plaques that honor Tennessee Williams and others, he says he’d like to help organize markers and walking tours that would publicize the town’s Black history.

“Think what that would do for a young person of color to learn that Nina Simone played at the A-House or that there’s a rumor of Grace Jones losing an earring on the dance floor,” Jackson says. “It’s part of the rich history of Provincetown, so let’s let people know.”

Don’t Tell Him No

The event: Broadway’s James Jackson Jr.
The time: Friday and Saturday, Oct. 11-12, 7:30 p.m.
The place: Post Office Cabaret, 303 Commercial St., Provincetown
The cost: $35-$40 at postofficecafe.net