DOCUMENTARY PREMIERE: Robert Klein owns a significant chunk of bragging rights in the history of premium TV: His 1975 standup comedy special for HBO was the network’s – and, thus, television’s – first unedited, full-length comedy concert. More than 40 years later, Klein gets a proper full-length salute: a documentary profile reflecting his long and influential career, which continues to this day. The title refers to the most famous, and very funny, bit from Klein’s early standup routine, which required him to provide his own harmonica accompaniment.