A playwright’s voice isn’t everything. Certainly not when it comes to our superficial enjoyment of a show. Watching a straight drama or comedy, we listen less for literary invention—the moments when language exists for its own sake, its own pleasure—than for themes and plot points that not only move the story along but also give us the sense, once the curtain falls, that the play has been a gratifying experience. But, periodically, playwrights come along who disrupt our spectatorial passivity by making our vibrant, boring, familiar, catchy, and idiosyncratic speech patterns strange and new. They do this by composing dialogue that works toward something far grander and harder to achieve than the usual he-said-she-said stuff: speech that is literature, representative of this world even as it creates another, in a kind of uncanny mimesis. The list of playwrights who have done this on the postwar American stage is relatively short, and ranges from Edward Albee, of course, and some late Tennessee Williams, to María Irene Fornés, Amiri Baraka, William Shawn, and Suzan-Lori Parks. These playwrights’ careers flowered at a time when it cost less to bet on a new artist. These days, playwrights who want to rival the richness and variety of their predecessors must also have the cunning to convince directors and producers of the political hipness or the professional advantageousness of their work.

The thirty-three-year-old Thomas Bradshaw—whose latest play, “Intimacy,” is at the New Group—has become a significant presence in the world of theatrical cool. The sixty-three-year-old John Patrick Shanley—whose new work is “Outside Mullingar” (a Manhattan Theatre Club production, directed by Doug Hughes, at the Samuel J. Friedman)—is technically and emotionally regressive. But, although the two plays couldn’t be less alike in subject matter or tone, they are both, ultimately, about the writer’s voice. Bradshaw’s goal is to make beauty out of the degradation that passes for everyday life—at least, where his morally compromised characters are concerned. And Shanley’s? In a way, his project is more complicated, because it’s both more outwardly sentimental and more inwardly closeted. Shanley coats his words in corn, to prevent them from revealing the truth, but about what? . . .