“Flower children of the ’60s” turned “fascist parents of the ’80s.”

“John and Jen,” a case study documenting this phenomenon, offers new insight into this perplexing yet prevalent development in American pop culture.

A senior project for Jessica Poter ’08 and directed by Rachel Hanson ’09, the complex musical goes up this weekend in Trumbull College’s Nick Chapel.

Written by Andrew Lippa and Tom Greenwald, “John and Jen” traces the dynamic relationships between Jen (Poter) and the two men in her life named John — her kid brother … and her kid (both played by Sam Bolen ’10).

“John and Jen” begins with the story of a brother and sister separated by six years but held together by an impenetrable bond of shared experience. Their strict, abusive father spurs Jen to take a protective hold — or vice grip — over her younger brother. While at home, they grow together, but once Jen goes off to college in New York, they grow apart.

By the time she finishes the “special” six-year program, Jen’s transformation into a war-protesting, drug-imbibing hippie is complete. And so is her brother’s: With crew cut and collared shirt, he is ready to enlist in the army and make his father proud. At their final meeting — before Jen runs off to Canada with her draft-evading, LSD-advocating poet boyfriend and John dies while serving in Vietnam — their culture clash comes to a head. The two trade serious blows that culminate in a bitter goodbye for both.

Alas, John lives to see another day, for he is reincarnated in her son … at least from the perspective of Jen’s psychologically damaged eyes. In reality, despite a persistent love for his distant grandfather, Jen’s son is not who her brother was: He rejects their Christmas song, he wants to leave home and become a writer and he smokes pot.

Informed by the drastically changing landscape of American society, the narrative is primarily the tale of Jen’s evolving relationship with her son as conditioned by her latent guilt for the loss of her brother. It revolves around the complications presented by an ever-living history, how that past dictates the present and the future and Jen’s struggle to let go.

The probing production begins on a note that tolls disaster, yet eventually flourishes into a fairly sophisticated exploration of human emotion.

Since the story portrays entire life cycles, the strangeness of the initial scenes is patently inescapable. Images of an adult actress sporting pigtails and a childish voice are never quite settling. Awkwardness aside, “John and Jen” survives by virtue of its persistent, onstage talent.

The syrupy-sweet nature of the narrative’s early scenes evokes feelings of an impending toothache, but as John and Jen mature, so does their story. By the second act, the production has drawn the viewer into the nuances of Jen’s development and her uncertain future.

However, this notable transformation is more a function of the story line than the actors presenting it.

Given size constraints of the stage and a minimal set — two chests, two chairs, one coffee table — it is impressive that by sheer imaginative force (and the addition of copious props, costume alterations and melodic shifts) the actors effectively conjure three distinct life stories.

The above-stage pit orchestra, featuring pianist Andrew Resnick ’08, cellist Paul Sherrill ’09 and percussionist Bix Bettwy ’08, supplements the cast’s efforts. Onstage costume changes and reorientations of the minimal set correspond to shifts in tone. The rhythm of the show is thus reflective of the percussion echoing from above the stage.

The production’s cast of two makes the feat all the more impressive. “John and Jen” is a labor of intensity and commitment; it is a delicate, two-hour duet.

Still, the quality of the singing and acting is marginally above average — just enough to keep the production moving. Although there is a clear conveyance of feeling, emotional scenes do not entirely convince. At times, the actors affect rather than internalize their feelings.

In “John and Jen,” comedy, drama and history merge, but as a result of missing nuances of emotion, the fusion is somewhat lacking.

For those seeking a fast-paced musical experience, they won’t find it here. But for those in search of a series of scrapbook-esque, nostalgic moments, “John and Jen” is an apt destination.