Even when it was new, 20 years ago, Peter Stein's staging of Verdi's last opera in the confined spaces of Cardiff's New Theatre was an oasis of clarity and good sense amid a sea of directorial postmodernism. Revived on Monday on the wider WMC stage, it had a faintly retro air, with the Globe-like balconies and arcades of Lucio Fanti's sets requiring lengthy scene-changes and two substantial intervals. No pacey modernism here, and not a Zimmer frame or an orange bowler hat to be seen. Moidele Bickel's costumes are about context, not subtext.
Stein has been back to rehearse the production, and it shows. Perhaps the original was sharper, more schematic in its choreography. The revival is messier, mildly less disciplined, and once or twice gratuitously vulgar, notably in the laundry-basket episode, where Stein invites laughter that covers Verdi's exquisitely scored love duet.
At the heart is Bryn Terfel's fat cavaliere, a performance of supreme artistry and musicality. It would be easy to think of Terfel as a creature of the media age. But the media age is lucky to have him. The voice, in every register, is in magnificent trim.
But that's only half the story. Few singers give more intelligent attention to what they are singing, the nuances of word and feeling, and few do less to hog the stage. This is a fat knight, but not too fat, though his paunch has its moments. The sight of him dripping like some half-drowned super-rat in Act III draws spontaneous laughter, but what follows silences mirth, so subtly does he tread the thin line between venom and venality, between word and melody – the essence of Verdi's technique.
But it's far from a one-man show. Vivid cameos by Anthony Mee (Dr Caius), Neil Jenkins (Bardolph) and Julian Close (Pistol) frame a brilliant Ford by Christopher Purves – himself a future Falstaff, but here in his element in Ford's jealousy monologue, which demands an old-fashioned Verdian temper otherwise lacking in this work.
Of the women, Claire Ormshaw's sparky Nanetta is the most ear- and eye-catching, but Janice Watson's Alice, Imelda Drumm's Meg, and Anne-Marie Owens's Quickly are all sound and excellent. Only Rhys Meirion's Fenton disappoints, needing more warmth, less sob. The WNO orchestra's playing under Carlo Rizzi is dazzlingly good.
Today and Sunday (0870 040 2000), then touring to 24 April ( www.wno.org.uk)