Some Village Folkways: Incest, Murder, Adultery.

The naked cowboy with the sequined phallus would be a startling apparition just about anywhere, with the possible exception of a gay strip club, but he seems a particularly incongruous vision in the humble Hungarian village of ''Peasant Opera,'' the quirky musical melodrama that opened Tuesday night at the Clark Studio Theater as part of the Lincoln Center Festival. Written and directed by Bela Pinter, a leading figure from the theater world of his native Budapest, with music by Benedek Darvas, the show is a ribald sendup of opera that blends the earthy sounds of Hungarian folk songs with the ordered conventions of baroque music, to strange but surprisingly satisfying effect. The story, drawn from a native folk tale widely known in Hungary, unfolds on the wedding day of Roland (Mr. Pinter) and his bride to be (Sarolta Nagy-Abonyi), whose obvious pregnancy doesn't appear to have dampened her blissful excitement. In the opening scene she sings merrily of her delight in the buds of springtime, which causes puzzled stares from the family gathered for the nuptials. ''Has she been drinking?'' asks one. ''Has she smoked a joint?'' As her betrothed informs her gently, the date is actually Oct. 28. [ABSTRACT FROM PUBLISHER]