Gray's monologue style and approach to theater had a signicant influence other performers and artists. The ripples of his autobiographical storytelling can be felt in writer/performer David Sedaris and his interviewing the audience probably made a show like James Lipton's The Actors Studio even conceivable. There were also influencers such as Samuel Beckett and peers like Eric Bogosian and Laurie Anderson that deserve a strong nod. Here a sample of some of the back and forth.
> My Dinner with Andre (film, 1981) - Two people talking over dinner feels today very much like Andre Gregory doing a Spalding performance for Wallace Shawn. A little shock to the world that watching a movie of two hours of dinner conversation -- albeit about spirital journey, rebirth and the struggle of meaning -- could be fascinating. Wallace as the voice of doubt and Andre as hope both managed to live and wrestle very much inside Spalding -- sometimes playfully, sometimes not. Even their creation method was similar to Spalding's early approach -- they taped their conversations for several weeks and then Shawn shaped them into a scripted conversation (purchase from amazon). His later work, The Fever, is a pure, personal monologue akin to Gray's work but with a more somber and dramatic theme. Available from Amazon (here) or there is a complete performance available for listening free from the Lannan Foundation (here).
> Inside the Actor's Studio (tv program, 2000) - Two people talking over glasses of water. Spalding's on stage interview format pointed back to the actor and their life. Talking about acting. Talking as acting. Who would have ever felt that being so personal was part of the craft, or talking about the craft was so professional. Very similar semi-famous program twenty years earlier was Donald Hall conducting deep televised interviews with dozens poets at University of Michigan with the same dilemma about talking about things in public as part of the art. Transcripts of those dialogues are still available.
> Samuel Beckett (plays, teleplays) - You can't watch Krapp's Last Tape and not see the desk of Swimming, to Cambodia, the recordings of past thoughts played back, over and over. Rumor is that Gray actually performed the piece at one point. Other Beckett works grind on the same reflection, humor, sadness, condition of things and turn out pearls. Perhaps New York and it's energy just added a different more frenetically modern twist to Gray.
> Eric Bogosian The film perfomance of Talk Radio was another solid take at translating the monologue style to screen, and more evidence that people would be willing to watch someone just tell a story. Many of his pieces are portraits or characters rather than pure narrative, but he's described them as fragmented part of himself and various archetypes. I don't know how explicitly they explicitly traded notes but they both helped build the semi-popular audience for performance art and the theatrical monologue.
> David Sedaris This great humorist and writer did his groundbreaking Santa Claus Diaries piece as a radio performance during the early years of This American Life. Eventually it spread through NPR and the rest is history. Many other early stories had their debut on the radio, and you get a sense that many pieces are written as a performance piece whether they're performed or not. The humor, intimacy and periodic surprise of seriousness is something Sedaris and Gray's work both share.