Observations: Hitler at the heart of Wagner

They've been called the "royal family" of Germany; their machinations have been compared to those of the power-crazed characters depicted in their ancestor Richard Wagner's Ring Cycle; and all of it is for the sake of power at the Bayreuth Festival, in Wagner's own opera house. The significance of the ongoing saga of the Wagner family is vastly increased by the fact that Adolf Hitler is intimately mixed up in the whole sorry affair.

It was only a matter of time before Tony Palmer, music documentary director par excellence, got his teeth into their story. Invited by Melvyn Bragg to contribute to the last-ever series of The South Bank Show, Palmer has produced a hard-hitting account that proves just how far some members of this family have gone to retain power. The content may not be entirely new, he says, "but what is new is the way that we have pulled the entire story together".

Most striking, of course, is the Hitler strand. The German dictator's notorious friendship with the English-born Winifred Wagner – wife of Wagner's son, the homosexual Siegfried – proved extremely expedient to him. "When he went to Bayreuth, the world took its eye off him: they thought he was just having fun at the opera," Palmer says. "But in fact he was sitting in the Wagners' house, planning the invasion of Poland with the children's geography textbook."

But the full archives remain closed. If the Wagner family is ever to come to terms with its history, Palmer suggests, the contents of those archives must be revealed. Then there will be a whole new film to make.

The South Bank Show screens Tony Palmer's 'The Wagner Family' on 13 September