Creative people of all kinds, but perhaps especially those involved in performing, love to talk about process, that mystery-shrouded road between the raw material of experience and the high finish of a work of art. Process is so fascinating, to insiders and outsiders, because it is hard to convey. Interviews with actors, directors and writers tend to devolve into truisms and abstractions, while attempts to dramatize artists at work often suffer from melodrama and foreshortening, missing the small details, the trial and error, and the sheer tedium of artistic labor.
All of which makes Michael Almereyda's new documentary, ''This So-Called Disaster,'' especially fascinating. Anyone interested in the challenges and techniques of acting -- which is really to say, anyone interested in human behavior -- should turn off E! and head down to Film Forum, where Mr. Almereyda's film opens today.
This director, whose films include the superb, cruelly ignored ''Hamlet'' starring Ethan Hawke and Julia Stiles, perched like a fly on the wall of a San Francisco theater in the autumn of 2000, all hundred of his eyes wide open. He was there to witness rehearsals for a production of ''The Late Henry Moss,'' a play by Sam Shepard, with a cast that included Nick Nolte and Sean Penn.
That play, later produced in New York with a different cast, revisits some of the themes -- manhood, fatherhood, the American West -- that animated Mr. Shepard's most famous plays of the 1970's and 80's. Mr. Penn and Mr. Nolte play angry damaged brothers who confront each other, after their father's death, in a trailer somewhere in the desert Southwest. Their father, the Henry Moss of the title, played with craggy, gravel-voiced gusto by James Gammon, is a raving, intermittently charming alcoholic, like so many of the fathers in Mr. Shepard's work. (And just about everywhere else in the canon of 20th-century American drama, come to think of it.)
Interviews with Mr. Shepard, who directed the San Francisco production, explore the connection between Moss and his own father, a World War II veteran whose life was derailed by drinking.
But the play's autobiographical resonance is only part of the what Mr. Almereyda's film is about. His unobtrusive, observant technique allows a complex alchemy of language, gesture and personality to emerge. Mr. Shepard and the principal actors talk, in interviews, about what drew them to acting, sometimes with reverence (Mr. Nolte recalls reading Stanislavski at a difficult time in his life), sometimes not (Mr. Penn recalls coveting a pair of zippered boots). Woody Harrelson, who plays a taxi driver in ''Henry Moss,'' cuts through the solemn Methodizing, playing dueling Brandos with Mr. Penn and telling him, ''That was a really underrated performance in 'Shanghai Surprise.' ''
The insights in ''This So-Called Disaster'' are numerous, small and hard to sum up: rather than analyze what actors do, Mr. Almereyda uses the techniques of cinéma vérité the way they use the Method, as a way to show, clearly and emphatically, what cannot quite be articulated. You sometimes suspect that ''The Late Henry Moss'' was less than the sum of its parts; it looks like minor, self-derivative Shepard next to the mighty mythologizing of ''Buried Child'' and ''True West.'' But the parts themselves, and the actors playing them, are odd, beautiful and full of life.