In the basement bar at downtown’s Gelso & Grand restaurant, Hot 97 DJ Mike Medium is spinning some boppy Rihanna songs for nearly 100 well-dressed, white-wine-sipping 20-somethings. But the real party, on a recent Wednesday night, had yet to start.

“I’m really hoping to see some great comedy tonight,” says Anusha Chemicala, 23, sitting in front of a small stage beside her friend, Humayra Kabir, 24. “I like how you can get really close to the comedians.”

It was the pair’s first Illuminati Party, a once- or twice-monthly event — the next one is Jan. 23 — founded in 2013 by comic Alexis Guerreros.

Billed as the city’s only invite-only stand-up comedy show, it aims to bring a more exclusive feel to New York locals looking for laughs — and not just through its invitation-only atmosphere.

Guerreros, 37, and co-host Mike Cannon, 33, both of whom have performed in comedy for a decade, want to let their big and rising-name friends joke in a smaller-scale space that prohibits filming, flash photography and the use of cellphones. Venues change, and the audience doesn’t know who’s performing until the comics take the stage. Previous guests have included Michelle Wolf, Michael Che, Hasan Minhaj and Chris Distefano.

Wednesday’s show, starting just after 9 p.m., featured Michael Kosta of “The Daily Show.”

“It keeps your comedy muscles sharp,” Kosta says at the end of his set — his third that night in as many city venues. He says audiences there are “ready to laugh — no one is on their phone and no one is heckling.”

As such, says Cannon, the Illuminati Party is a good place to workshop a routine and try out new material that, thanks to the ban on filming and phones, won’t end up on the internet.

It’s also a place, Guerreros says, where there’s no pressure for comics to be perfect.

Better still, at least for the audience, is that the show is free. First-timers seeking an invitation must enter their name, email address and Instagram handle into the PartyIlluminati.com database, where they’re randomly chosen to attend upcoming shows. Those who’ve already attended receive an email with a private link for upcoming events.

On Wednesday night, Vladimir Caamaño, who’s appeared on “Jimmy Kimmel Live,” was recalling his Bronx upbringing in a Dominican household (telling the audience how his father pronounces his nickname, Vlad, like “Blah”). Canadian comic Alex Pavone joked about leaving Ontario for America to make it, only to now live in a Queens apartment with three roommates.

Even the invitation-only nature of the show became a talking point.

“So you were all invited to be here?” stand-up comedian Dina Hashem, who’s performed on “Conan,” asked the crowd. “Does everyone here have power?”

Wednesday’s crowd was made up mostly of first-timers, but a few repeat visitors were there, too.

“There are people who get to know us on a personal level,” Cannon says. Says Guerreros: “We’ve had audience members remember our birthdays or know our wives’ names without ever meeting them.”

And there’s a simple reason why some show up again and again.

“You laugh for an hour,” says Leah Kraehling, a model who was at her second Illuminati Party, “and leave feeling good.”