Hardly as salacious as its name suggests, the documentary “Sex and Broadcasting — A Film About WFMU” paints an affectionate portrait of this Jersey City radio station (91.1 FM in the New York City area, and 90.1 in the Hudson Valley), which remains listener-supported at a time when corporate or umbrella funding is the norm. (The first half of the title comes from a book on community radio by Lorenzo W. Milam.)  Matt Groening, creator of “The Simpsons,” and Lee Ranaldo of Sonic Youth both praise the programming, known for its eclecticism and rebelliousness. The film’s director, Tim K. Smith, shows WFMU mixing styles and genres (the playlist includes undersung bands alongside a man who makes music on glassware) as freely as it mixes politics. (Nachum Segal, the voice of its show “Jewish Moments in the Morning,” gets a testimonial from Rush Limbaugh.)  Ken Freedman, WFMU’s manager, speaks of challenges from the recession, copyright issues and competitors — problems that the movie could have explored more deeply. Skimming the details, the documentary observes Mr. Freedman’s race against a deadline from the Federal Communications Commission to finance a signal-boosting tower in New York City. “Sex and Broadcasting” also shoehorns in some of WFMU’s six-decade history: It began operating out of Upsala College in East Orange in 1958 and moved after the college closed in 1995.  Professionally comfortable with improvising, the D.J.s make for affable company, and it’s amusing to watch radio from behind the scenes. But a tinge of melancholy also hovers over the movie, which suggests that success has a ceiling at a station where even stars go unpaid. Tom Scharpling, seen as a devoted host of “The Best Show on WFMU,” eventually leaves. He has spun off his show into a popular podcast.  “Sex and Broadcasting — A Film About WFMU” is not rated. Running time: 1 hour 18 minutes.  A version of this review appears in print on March 30, 2016, on page C6 of the New York edition with the headline: What Radio Sounds Like, Hanging by a Shoestring. Order Reprints| Today's Paper|Subscribe
The story of WFMU, a listener-supported radio station kept alive in the era of corporate financing by sometimes wacky labors of love.