Mohsen Namjoo plays a station manager at the fictional PARS-FM in “Radio Dreams.” (Matson Films)

An anticipated appearance by Metallica looms as mythically large as a visit by Beckett’s Godot in Iranian-British director Babak Jalali’s genre-defying “Radio Dreams.”

The film charts two paths: the struggles and dysfunctions of fictional San Francisco radio station PARS-FM as it documents the Iranian immigrant experience; and the real-life Afghan rock band Kabul Dreams, whose members, in the film, have traveled across the world to perform with Metallica in the station’s ramshackle studio.

Documentary-style interviews that shed light on the band’s backstory and aspirations are woven with stylized dialogue by Jalali and co-screenwriter Aida Ahadiany that dryly savages the station’s mismanagement: An “on air” sign is hung upside down, a bass guitar goes missing, and an inept musician interrupts a woman’s heartfelt story of assimilation when he interrupts her with a tacky jingle. These Christopher Guest-like antics help create a rich tension between fact and fiction that drives the film as it explores uncharted territory of the mockumentary.

The station’s program director (and the film’s protagonist), Hamid, is played by Iranian singer-songwriter Mohsen Namjoo, who has a knack for deadpan delivery and a wild mane of graying hair that foreshadows impending chaos. When Kabul Dreams finally does play a song near the end of the film, it may spark a desire in viewers to see a more straight-faced documentary that is solely about them. But Jalali has grander ambitions, mining the symbiotic relationship between humor and despair to show us the often-isolating experience of the immigrant. Feelings of displacement — of loss of home, country and language — are balanced by the vivid imagination of a better existence. In other words, “Radio Dreams” is a quintessentially American story.

Unrated. At area theaters. Contains strong language and adult situations. In Farsi, English, Dari and Assyrian with subtitles. 91 minutes.