Martin Scorsese's film 'New York, New York', starring Robert De Niro and Liza Minnelli, is his most ambitious film to date. Not just a nostalgic homage to the Hollywood musical but a personal work that means as much to him, says Scorsese, as 'Mean Streets' and 'Taxi Driver'. Gavin Millar talks to Scorsese in San Francisco and the programme includes rare interviews with Robert De Niro, Liza Minnelli, and Jodie Foster.