New in 2011, Sebastian Baumgarten’s Tannhauser is the third of the five 2012 Bayreuth Festival productions to superimpose the concept of its protagonists being the unwitting subjects of a sinister experiment conducted by powers unknown (also implied in Hans Neuenfels’s Lohengrin and Christoph Marthaler’s Tristan und Isolde). What they are driving at is anyone’s guess. In this case Baumgarten is possibly reflecting the hero Tannhauser’s own experiment with carnal excess.

Opera should challenge and provoke. When they were new, Wagner’s music dramas were shockingly avant-guarde, and they can still be today - but the current trend for layering additional, often contradictory, notions over the composer’s own is counter-productive. Joep van Lieshout’s money-no-object set - a vast multi-floored industrial plant construction and caged Venusberg love-grotto which rises from the ground - is undeniably impressive, but it is impossible to take any production seriously that features dancing sperms.

Thankfully, the solid and inspiring presence of peerless Wagnerian Christian Thielemann in the pit ensures high musical values, as does the excellent cast - streets ahead of any other at Bayreuth this year. The top accolade goes to Camilla Nylund, whose Elisabeth has an ideal balance of power tempered with creamy beauty. Michelle Breedt’s Venus is similarly strong, as is Michael Nagy’s Wolfram - his exquisite O! Du mien holder is a highlight. Torsten Kurl’s Tannhauser has an easy fluency, and each of the smaller roles is well delivered. With the festival chorus and orchestra on majestic form, the music - Wagner’s most conventionally tuneful - is frequently spine-tingling, resounding splendidly in the marvellous Festspielhaus acoustic - a true wonder of the modern world.