‘Don’t Think Twice’ explores world of improvisational comedy

Are there people who don’t know what improvisational comedy is?

Writer-director Mike Birbiglia seems to think so, because he begins his new film “Don’t Think Twice” with a short history of the development of improv and an explanation of the rules, such as the way each new onstage inspiration requires a “Yes, and…” response from the other player in order to keep the sketch going.

This primer makes the film stumble out of the gate, but all right, the rare individual who chooses to see a film about improv comedy without knowing how it works will be up to speed. Happily, the film does not feel the need to explain itself thereafter, and we are free to enjoy a pleasantly low-key comedy-drama credibly laced with disappointment and frustration—and the occasional onstage high.

The group in question is known as the Commune, seven friends whose long-running act is getting squeezed by the dire economic realities of New York City rent and, more importantly, by the fact that they’ve been doing this a while and have yet to break out into the big time.

The chemistry changes when a producer from “Weekend Live” (a brutally obvious takeoff of “Saturday Night Live”) attends a show. Commune cast members Samantha (Gillian Jacobs) and her boyfriend Jack (Keegan-Michael Key) are called to try out for “Weekend,” an opportunity that inspires clenched-teeth congrats from the rest of the group.

Jack nails the audition and is hired, but the conflicted Sam doesn’t even show up. She prefers the small joys of making ephemeral magic on a live stage.

Those two are the standout characters, although we spend time with the others as well. Birbiglia plays Miles, the leader of the Commune, who teaches improv workshops and likes to tell his young, pretty students about how he started the group and personally coached now-famous comics.

There’s an edge of desperation around his patter, because at 36, he realizes he’s never going to be hired for “Weekend Live.” And if that brass ring is no longer dangling, what else is there?

Then there’s Lindsay (Tami Sagher), whose family has money, which makes her vaguely suspect in the eyes of the others. Allison (Kate Micucci, half of the comedy act Garfunkel and Oates) wants to draw a graphic novel, and Bill (Chris Gethard) is dealing with his father’s serious illness.

In short, many things conspire to make these friends question how much longer they can do this. As a director, Birbiglia has a gentle touch, as he proved in his autobiographical directing debut, “Sleepwalk with Me” (both films are produced by “This American Life” guru Ira Glass).

This movie has a few hard feelings and one thrown punch, but Birbiglia prefers to capture a detailed world and its relationships, not hunt for the dramatic beats. The tiny apartments and crummy backstages look authentic, and the mixed feelings about the success of Commune members makes “Don’t Think Twice” honest about the tricky business of having friends engaged in the same creative enterprise you practice.

The onstage scenes give evidence of how the delicate interplay of improvisation operates, including examples of showboating (a cardinal sin, as the process is meant to be about the group dynamic, not the skills of individuals). Nevertheless, the film itself allows for two knockout individual performances.

Birbiglia keeps this all modestly humming, and maybe its appeal won’t extend too far beyond an audience already interested in how showbiz works.

But the final sequence suggests some canny storytelling skills, as the plot returns to the comedy-club stage and a resolution is played out within the framework of a live show. This final scene allows “Yes, and…” to culminate in a nice blend of the sad and the sweet.

“Don’t Think Twice” (3 stars)

Comedian Mike Birbiglia writes and directs this funny-sad look at a group of improvisational performers, whose camaraderie frays when one (Keegan-Michael Key) is hired for a network comedy show. A nice low-key mood, and an excellent performance by Gillian Jacobs, make this character study work.

Rating: R, for language, subject matter

Showing: SIFF Cinema Uptown