Boulez’s recordings become more precious the less we hear from him. He still has so much to say about the music of the past – and hopefully the future. Here he explores the life-stories teeming beneath the shells of two musical organisms with murder in mind, often told through mutated forms of the waltz. He had not conducted the opera complete before he made his first recording of the Suite (Sony, 8/79), which is a comparably prosaic and distant reflection of Berg’s original title, ‘Symphonic Pieces from the opera Lulu’, whereas every smoochy, sleazy bar of this live recording benefits from the Vienna Philharmonic having played the opera during the previous year’s Salzburg Festival. He now dispenses with the scream that only anticipates the final orchestral shudder, which is even less formal and more horrifyingly matter-of-fact than before.

Mahler’s revision, Boulez’s approach and the expressionist lens of DG’s close-up sound picture effectively combine to throw a curtain over the background of Das klagende Lied in Wagner, Bruckner, even Brahms’s Rinaldo, and present a painfully familial tragedy on a claustrophobic proscenium – Boulez’s ‘theatre of the mind’, with the spectre of Duke Bluebeard’s Castle present yet unseen like the flute’s song of fratricide. With Anna Larsson as the narrator, we’re reminded how dynamically her part stands between Erda and Schoenberg’s Wood Dove as the voice of bitter reason. Röschmann and Botha, meanwhile, make smaller but thrilling contributions.

My other ungrateful reservation concerns the absence of Der Wein with Röschmann, present on C Major’s video of the same concert: for a slightly less close-miked sound, and if you’d like to see as well as hear Mahler’s offstage bands, then the Blu-ray is an essential purchase.