Daniel Barenboim’s celebration of the Wagner bicentenary culminated in the completion of a new Ring cycle, produced by Guy Cassiers, mounted in Berlin and Milan, and given a concert staging at the BBC Proms. These DVDs of La Scala performances, combining the October 2012 Siegfried with the June 2013 Götterdämmerung, are most notable for showcasing this conductor’s supreme command of the epic lyricism that goes to the heart of the Wagner style; and while some might regret the absence of the Staatskapelle Berlin, whose playing was a highlight of the Proms performances, the La Scala orchestra has no weak links either.

Barenboim’s flair for drawing out often under-characterised details, as with the string-writing in the Götterdämmerung funeral music, is one outstanding feature. Even more important is his melding of space and time to ensure that the full eloquence of the musical drama can be conveyed without exaggeration or treading water. I don’t think I’ve ever heard less episodic accounts of the immense structures of Siegfried’s third act or the first act of Götterdämmerung. So, even when reservations about singing, staging and filming are all factored in, this is an absorbing portrait of a fine Wagner conductor at the height of his powers.

Cassiers’s production is rather artful in combining quite traditional demands on the singers with a setting that employs simple structures – representing Mime’s forge, Brünnhilde’s rock, the Gibichung’s hall, and so on – against a high-tech background of projections that mix abstract and naturalistic images for reasons which the booklet-notes attempt to explain. Viewed on a small screen, there’s an element of neither one thing nor the other about this but, given the musical virtues, the setting contributes enough atmosphere to the staging to be acceptable in its own terms. The film technique of frequently fading out singers to show some of the set before fading them in again takes some getting used to but can’t be rated a serious drawback, irritating though it is in places.

As for the singers: there’s the considerable plus of a pair of Brünnhildes, Nina Stemme and Iréne Theorin, whose sumptuous voices serve both the human and mythic aspects of the drama to admirable effect. Anna Larsson as Erda and Waltraud Meier as Waltraute are no less memorable in their smaller roles. Much of the focus is on Lance Ryan’s Siegfried, aggressively saturnine rather than naively jovial, and even more prone to project harshly in the second opera than the first: in this context, the more intimate declamatory style he finds for Siegfried’s final narration is gratifying and shows that he can call on something more than mere stamina in delivering these punishingly demanding roles. No disappointments with the other male singers – just a pity that the producer has Hagen address the audience rather than the vassals assembled behind him in Götterdämmerung Act 2. This underlines that while Cassiers achieves an uneasy compromise between tradition and innovation, Barenboim provides a masterclass in Wagner interpretation that need fear no comparison with the greatest of his precursors.