On October 10, Hamptons International Film Festival screened “Ron Delsener Presents,” a film directed by Jake Sumner that pulls back the curtain on Delsener’s 60-year career as a concert promoter and showman. In a certain era, the three words “Ron Delsener Presents” preceded the name of every major act playing New York, from The Beatles at Forest Hills Tennis Stadium to David Bowie at Carnegie Hall and Patti Smith at the Palladium. The film takes audiences on a tour through a half-century of live music and offers a portrait of a music business pioneer who, to this day, can’t stop hustling.