"Greetings From Tim Buckley," a new film that premiered at the Tribeca Film Festival Tuesday, is a biopic of famed 90s rock singer Jeff Buckley -- just not in the traditional sense. Rather than chronicling his most famous period (the release of his acclaimed debut "Grace" in 1994 and the fatal, fully-clothed swim in Memphis that led to his death at the age of 30 in 1997) the film instead takes place over a few days in April 1991.