Set dates for previews, openings and closings. Fall and spring seasons. Heck: turning up somewhere on time!

Until the pandemic occurred in 2020, many of us perhaps did not realize how much theater relies on appointments. Now that most of them have vanished, with theater — and time itself — becoming somewhat amorphous, it’s comforting to see that the January festivals are still happening.

Once cursed as the sluggish period of the year that follows the holiday rush, January has slowly turned into a hyperactive showcase for experimental work. And so it remains this year. While the doors remain physically shut, our minds can still open up.

Under the Radar

In a way, going online was a natural step for Under the Radar (through Jan. 17). Hosted by the Public Theater, the 17-year-old event has always questioned the very nature of the art form: “What makes something theater?” the festival director Mark Russell pondered in a recent video chat. “Can an exhibit be a theater piece? Does a story have to be a part of it? This is a lot of hubris, but I felt like the whole world turned into UTR,” he added, laughing.

One thing that has not changed is Under the Radar’s international bent — this year with a mix of on-demand and appointment shows, all of them free. Among the on-demand offerings are works in which two wildly creative women take on roles different from the ones they’re known for: “Capsule,” in which the rising director Whitney White (“What to Send Up When It Goes Down”) steps on the virtual stage; and “Espíritu,” which was written and directed by the prominent Chilean actress Trinidad González (“A Fantastic Woman”).

As for the livestreams, mark your calendar for Piehole’s “Disclaimer”; “Borders & Crossings,” by the Nigerian-British playwright and performer Inua Ellams (“Barber Shop Chronicles”); and “A Thousand Ways (Part One): A Phone Call,” by 600 Highwaymen.

Prototype

The experimental operas and musical-theater pieces that the Prototype festival presents can take three to five years to gestate. So when the artistic directors Beth Morrison and Jecca Barry (from Beth Morrison Projects) and Kristin Marting (from HERE Arts Center) decided in June to jettison the entire slate they had planned for the 2021 edition, which runs from Jan. 8-16, they knew they would have to change tack, and fast. Especially since they did not want to simply adapt pre-existing projects for the digital world.

“A bunch of people came in with stuff that was like retooling things that they already had,” Marting said. As curators, they felt that this “wasn’t the way that we can serve our audience right now,” she continued.

The new 2021 festival centerpiece, “Modulation” — a commission made up of brief vocal works by the likes of Sahba Aminikia, Juhi Bansal, Yvette Janine Jackson, Angélica Negrón and Daniel Bernard Roumain — emerged as a pure product of the new moment.

“We saw the opportunity to ask a lot of composers to respond to 2020, but in short bursts,” Barry said. “The three of us developed different themes for what we were interested in having them respond to, and we landed on fear, isolation and identity. Then we thought of a fourth theme to connect all of those things, and that was breath.”

Except for “Ocean Body,” a ticketed video installation at HERE that features the performers Helga Davis and Shara Nova, all of Prototype 2021’s offerings are on-demand. This includes Geoff Sobelle and Pamela Z’s “Times³ (Times x Times x Times),” which can be streamed anywhere but was conceived to be heard while walking through Times Square. For Marting, the experience is typical of Prototype’s ever-questioning approach. “We’re trying to craft the conversation,” she said, “because one of the things the festival is really interested in is interrogating this line between opera and music theater, and why people think they like one and not the other.”

Exponential Festival

“We didn’t want to do a single Zoom reading because they’re the bane of my existence,” said Theresa Buchheister, the founding artistic director of the Exponential Festival.

This is pretty much the only guarantee we can get about the 2021 edition of a fest that reliably supplies the nuttiest, most unpredictable programming of any in January.

In normal years, the festival takes place at such funky Brooklyn venues as the Brick Theater, Vital Joint and Chez Bushwick. But from Jan. 7-31, each of the 31 shows on the 2021 slate will debut in one place — YouTube — and will remain available for the foreseeable future. While this is convenient for viewers, it is giving Buchheister an extra headache. “We’re dealing with nudity on YouTube, which is hard,” she said. “Performance artists are always naked, they just are. So it’s one of the many difficulties this year.”

Indeed, challenges abounded. Another, for example, was figuring out how to present Panoply Performance Laboratory’s “Heidegger’s Indiana,” which Esther Neff originally envisioned as a choose-your-own-adventure show made up of distinct vignettes.

“What we ended up doing is that Esther will create a work where she’s put the pieces in the order that she wants,” Buchheister said. “And I was like, ‘You can draw tarot cards, you can throw axes into a tree — I don’t care how you choose what order they go into.’ But then we’ll also create a playlist on YouTube of all of the different segments.”

One of Exponential’s singularities is its emphasis on curated bills, often pairing a better-known — at least in avant-garde circles — with an up-and-comer. Buchheister was excited to link the writer-performer Jess Barbagallo and the musician Nathan Repasz. “Nathan did one of my favorite performances of 2020,” she said, “a percussion piece to Mitt Romney saying that hot dog is his favorite meat.”