Her stage world shows symbolisations of the emotional geography of Wagner’s drama. Act 1 is a Piranesi-like assembly of mobile stairs and walkways, hindering the would-be lovers from getting together as unconventionally early as they wish. Act 2 is a prison yard monitored from above by Marke, Melot and guards. It features self-activating metal bar cages, over the largest of which the lovers – at the expense of bleeding – gain some control. Act 3 is just a narrow lit space in the darkness where Kurwenal, the Shepherd and some retainers sit by the dying Tristan. In his delirium, Tristan thinks he sees ‘Isolde’ (a sequence of doubles or models, some of which collapse alarmingly, or bleed) in raised triangular lit spaces. As soon as the Liebestod is over, Isolde (as at the end of Act 2) is led away forcibly by Marke, as if back to her wifely and regal duties.

The concentrated acting performances are closely supported by Christian Thielemann’s approach, a marked contrast to his rather unspecific live recording of the piece from Vienna (DG, 8/04). He’s not afraid here to sound deliberately un-beautiful when the staging needs it – try the distractions to the lovers after the (here) pouring away of the potion in Act 1 or Tristan’s first monologue when Isolde’s ship doesn’t arrive in Act 3. Or to vary tempi much more widely than, say, Karl Böhm (DG and other labels, Bayreuth 1960s) for Tristan’s arrival in Act 2 (very fast) or the Liebestod (pretty broad). Like the staging, this is not a Romantic reading.

Evelyn Herlitzius delivers the Act 1 narratives with fury and power, and seems later not to be outsung by Stephen Gould’s noble, larger-sounding Tristan. The tenor is especially impressive in his untiring handling of Act 3’s delusions. Both show immense understanding of and ability to communicate their complex texts at every moment. Georg Zeppenfeld’s often cruel, unforgiving Marke captures a wider range in the role than many – from sadistic jokey involvement in his Act 2 spying role to genuine horror when he sees and hears the lovers’ declarations. He wears his imaginative costume and Homburg hat well – a flamboyant Visconti-esque yellow standing out from the drabber colours around him. Iain Paterson is both inexhaustible and moving in his understatement of the frustrations and emotion of Kurwenal’s support for Tristan.

Michael Beyer’s video direction sometimes takes the imaginary spectator up into the fly galleries of the theatre, the better to picture the stage layouts beneath. The Blu-ray mode itself is predictably sharp throughout and most effective in picking up detail in the darkest moments of Act 3. This is an important and compelling addition to the number of worthwhile interventionist Bayreuth productions of the opera already captured on DVD.