There's a case to be made for experiencing Wagner an act at a time, and the concluding part of Siegfried is particularly effective as an autonomous entity. It's the point at which Wagner resumed work on the Ring after a 12-year gap, and is suffused by a renewed sense of energy. It also marks the point where the older generation is supplanted by the new, as Siegfried dismisses Wotan with the decisive arrogance of a teenager telling his granddad to get lost.

Mark Elder's concert performance with the Hallé was a rare opportunity to hear the Canadian tenor Ben Heppner sing Siegfried in the flesh. As with most tenors with the physical capacity to sustain the role, there's a fair amount of flesh to hear him in; but his voice is an exceptional instrument, enormously robust but never harsh or squeezed under pressure.

Irene Theorin is fast developing into one of the world's busiest Brunnhildes, and her sumptuously expressive performance makes it clear why. Many sopranos emphasise the shrill bluster of the Valkyrie: Theorin reveals the vulnerable girl beneath the breastplate. Johan Reuter has a more difficult task imposing his authority as Wotan/the Wanderer, who by this stage in the opera is largely a spent force; but Anna Larsson's Erda is so chilling you can almost hear the frost on her vocal chords.

Concert performances are not always ideal - it's inevitably disappointing when the libretto calls for the hero to plunge into a ring of fire, but all that happens is a large man in a tuxedo sits down. Yet it throws the orchestral sound-painting into even sharper focus: the famous chromatic climb of unaccompanied violins is not only an evocation of Siegfried's ascent, it is the sound of Elder pushing the Hallé to greater heights.