The Bee Gees (Maurice Gibb, Robin Gibb and Barry Gibb) in 1979. (Photo by Ed Caraeff/Getty Images)
CNN  — 

Knowing the songs isn’t knowing the whole story with “The Bee Gees: How Can You Mend a Broken Heart,” the HBO documentary you probably didn’t know you needed. That’s because this infectious film goes beyond mere nostalgia in chronicling the roller-coaster ups and downs of the brothers Gibb, which should make anyone even mildly familiar with the group feel a little “Fever”-ish.

Director Frank Marshall kicks off with the brothers – Barry, Robin and Maurice – performing at a rapturous arena in 1979, two years after the “Saturday Night Fever” soundtrack unleashed a flurry of hits, while sowing the seeds for what would become a backlash against disco music. The film then jumps 40 years ahead, to an aged Barry, last surviving member, who ruefully cites his memories and says, “Someone will be left in the end.”

What follows consists of multiple parts, including the brothers’ unique collaborative style – actually writing songs in the studio while recording – exploring the challenging dynamics of working professionally with family and charting the Gibbs’ rise, breakup, reunion, staggering success, the radioactive period that came after, and finally a measure of redemption.

Beyond Barry – three years older than his twin brothers, and a dozen older than Andy, who became a teen heartthrob as a solo act – Marshall and writer Mark Monroe talk to numerous associates and shrewdly solicit third-party voices like Justin Timberlake Nick Jonas, who in the latter case can address the complications associated with having a musical enterprise with siblings.

Perhaps what comes through the loudest is the idea of the Bee Gees as “chameleons of pop,” as one critic puts it, repeatedly reinventing themselves in the process.

pmt barry gibb on surviving his brothers_00004627.jpg
Barry Gibb on losing his brothers
01:09 - Source: CNN

That included basically stumbling into their falsetto singing style on the song “Nights on Broadway,” then consciously pivoting to exploit it on “Saturday Night Fever,” whose wild popularity – yielding four No. 1 hits – not only powered the movie but played a direct role in producer Robert Stigwood securing the wide release from Paramount that fueled its box-office bounty.

“How Can You Mend a Broken Heart” (a title derived from another hit) is full of such anecdotes. To cite a few, there’s father Hugh pushing them, stage-dad style, in their early years; “You Should Be Dancing” exploding in gay clubs that drove the disco craze before it percolated into the mainstream; and other artists seeking them out to write hit songs after the band’s shine faded. Pop staples like Barbra Streisand’s “Woman in Love” and the Dolly Parton-Kenny Rogers duet “Islands in the Stream” were the result.

Still, the ebullient, at-times joyous nature of the music is offset by the melancholy tone of the film, which makes a pretty convincing case that the Bee Gees – for all their gaudy gold records and even gaudier gold chains – were underappreciated and, in some quarters, disproportionately vilified.

“When you become famous you think that everyone loves you, and they’re gonna love you forever. And it’s not true,” Barry says.

The Bee Gees were adored, hated and as seen through Marshall’s lens, somewhat forgotten. Yet after watching this documentary, even if you didn’t have an especially deep love for the band in their heyday, you might find yourself humming those tunes all over again.

“The Bee Gees: How Can You Mend a Broken Heart” premieres Dec. 12 at 8 p.m. ET on HBO, which, like CNN, is a unit of WarnerMedia.