The Woman without a Shadow, completed during the First World War but not staged till 1919, was Hugo von Hofmannsthal’s third operatic collaboration with Strauss, after Der Rosenkavalier and Ariadne auf Naxos. Conceived as an analogue to The Magic Flute, it follows the progress of two contrasted couples: not towards enlightenment but towards starting a family. The libretto is dense, not to say foggy. Does the shadow denote pregnancy or simply the ability to bear children? What lies behind the ambivalent role of the Nurse? The audience needs all the help it can get. It doesn’t get it in Robert Carsen’s current production at the Vienna State Opera, where the Empress spends much of her time in bed; and it certainly doesn’t get it here.

For this is no staging but a concert performance with a difference. Christof Loy has set the opera in the Sofiensaal in Vienna and the ‘action’ is the recording made by Decca in 1955. So for much of the time the characters clutch vocal scores and sing from music stands. The Nurse wears hat, coat and gloves, the Spirit Messenger a coat and scarf (the hall was unheated, according to Loy). Assistant producers move stands and singers around. During an orchestral interlude, Barak leaves the stage for a drink and a smoke. Moreover – though you wouldn’t know without reading Mike Ashman’s booklet-note – Loy sees the Empress as a young singer learning from her more experienced colleagues.

It’s all a long way from the original but if you can accept Loy’s reinvention there’s much to admire. One or two imprecise entries aside, the Vienna Philharmonic play like angels: Christian Thielemann is alive to every detail of Strauss’s kaleidoscopic orchestration. As the Empress, Anne Schwanewilms is outstanding, her gleaming soprano scoring bullseye after bullseye. Michaela Schuster’s subtle facial expressions are well caught by the camera but the close-ups of Evelyn Herlitzius are less than flattering. Wolfgang Koch is a sterling Barak; Stephen Gould has the top notes but it’s hard to be moved by the Emperor’s Act 2 solo when you have just seen him take a sip of water.

Götz Friedrich’s production for Solti (Decca) is reassuringly traditional; Ennosuke Ichikawa’s for Sawallisch (ArtHaus Musik), better sung, makes a number of cuts. Thielemann/Loy is absolutely complete, including all the Empress’s spoken words in Act 3.