One year on from Live8, Roger Waters returns to Hyde Park, the scene of his one-off reunion with the band he’s been estranged from for 20 years, to headline the first night of the Hyde Park Calling festival. Warner had a famous run-in with the vigilant Beckett estate when it banned her production of Footfalls, but when it lost its recent case against a cross-gender Godot in Italy, she and the NT thought “the writing was on the wall and that we were in with a chance with this fantastic proposition of a cast”. Warner-watchers will be intrigued to learn that at the end of this year, she was to have to have directed “two major actresses” in a taboo-busting Waiting For Godot at the National. I’m not sure that Bill would sustain it that long in a recording, but you can’t disapprove of it in the theatre, because it held that stage”.Her future plans include an ENO Death in Venice and Poulenc’s La Voix Humaine for Opera North.

He lets me speak about tempi and he’s been of great help to me in bringing out the musical expressiveness of the spoken dialogue”. Talking generally of relationship between director and conductor, she cites the dramatic potency of complete pauses in the music if the director can justify them to a conductor, in whose gift they are. In her Vienna production of Dido and Aeneas earlier this year, she persuaded William Christie to “allow an extended pause in which everything stopped while Dido went through the stages of thinking, ‘Aeneas has gone; I’d have him back; no I don’t want him to come back; I’ve got to go forward, and now I’m moving towards the abyss’. The audience will be left to make of that what they will.Warner’s production also draws attention to what she calls the “unsteadiness” of the ending. The distress of Marzelline, whose love Leonore has exploited, is realistically highlighted Snow falls on the jubilant reunion of prisoners and wives. “It’s a party, but how long can it last?” asks Warner.She’s renowned for leaving no received wisdom untested.

I wondered how this worked when, as in opera, two people are in charge. She talks about how she and Mark Elder, who is conducting Fidelio, are “sensitive to what the other does and heading in the same direction. Warner has resisted the temptation to convert the prison into Guantanamo, but it will be lightly intimated in the finale that it has taken a foreign liberation force to upset the status quo. Florestan has been missing for two years and I don’t reckon this is the first prison where she’s looked for him. Anja’s exploration is of the really complicated area of being in a despair that, because hope is so much her philosophy, Leonore cannot even confess to herself.”The atrocity of the World Trade Center and George W Bush’s “war on terror” were still to come when the production began life in May 2001. Warner singles out two lines from that aria where the heroine sings (in the original German at Glyndebourne) “Sweet hope, oh never let your star,/Your last faint star of comfort be denied me” (Warner’s italics).

Because Kampe is willing to experiment as an actress, they have been investigating the possibility that at the start of the opera, “Leonore is on the point of losing it and giving up. He pushes Leonore to the absolute edge in her aria and Anja is prepared to try it in rehearsal again and again and again”. That, for Warner, is the key, because the intrepidness of the artist mirrors the courage of the character.”People say that it was Beethoven’s mistake or his unkindness that he has people singing on their break in such an uncomfortable place for them But actually I think it’s fundamental. While Charlotte Margiono was deemed to have brought exquisite musicianship to the role, “one has,” according to one reviewer, “to shut one’s eyes in order to be moved by her”.To judge from the run-through I witnessed, eyes will widen (and ears pop) in awe of Anja Kampe, the German soprano who caused a sensation when she played Sieglinde opposite Placido Domingo in Washington Opera’s Die Walk? She’s beautiful, very believable as a male, and she sings with extraordinary fearlessness, even in a piano rehearsal where singers tend to save their voices. “I came away from the first experience of directing Fidelio feeling that it was a thrilling piece, but thinking maybe one could never get together a cast that could properly inhabit it”.