Two paths wind on to the stage and swirl into the mythological crossroads that Robert Johnson, the great grandfather of American blues music, sang about in the late 1920s. With his music, he captured the essence of the black experience in the South during the early part of this century. The Arena Stage’s production of “Thunder Knocking on the Door” takes a snapshot of a family caught in the rawness of that experience, examining its daily life through the context of blues music.

The plot unfolds as traveling bluesman Marvell Thunder (Peter Jay Fernandez) arrives at the door of the Dupree family looking to settle a cutting match (guitar battle) with Jaguar Dupree Jr. (Doug Eskew). In a previous match with Thunder, Jaguar lost his deceased father’s guitar. Magically restoring vision to Jaguar’s blind sister Glory (Marva Hicks), Thunder sparks her heart and challenges her to a guitar duel.

From hopeful beginnings, the play assumes the formulaic plot of the average love story sprinkled with the dust of Southern blues folklore. The opening scene refers to the bluesman as a Shakespearean figure seeking fortune and defending honor. The repeatedly stated mission of the blues sojourner – to “take on the role to seek the truth” – is compelling

But the production never follows through on the intriguing promises of the first scene. Writer/director Keith Glover turns his back on opening-scene intentions of exploring themes that lie beneath the chords of the primordial 12-bar blues progression – the reconciliation of suffering, the defense of personal dignity and the politics of women and family.

Although modern blues great Keb’ Mo’, along with Anderson Edwards, penned the songs, the music is plagued by loud but thin electric guitars and microphoned voices, negating the rough antiquity of acoustic instrumentation and the unamplified moaning voices that form the heart of delta blues. Musical weakness accompanies a plot that reconciles life’s trials and tribulations through veiled discussions of the form and significance of blues music, but never transcends surface sentimentality.

Valiantly armed with powerful voices – though the use of individual, face-mounted microphones makes the power questionable – the cast members often spin into energetic, sometimes comical interactions. Still, they cannot escape the limitations of the script or the generic songs, which too often imitate blues music rather than manifest the spirit of the blues. Ultimately, Glover sacrifices meaningful examination of the Dupree family for light entertainment.

“Thunder Knocking on the Door” continues at the Arena Stage through Dec. 27.