Anne Sofie von Otter is a Swedish mezzo-soprano whose shape-changing puts Proteus to shame. I have seen her as a succession of haughty male aristocrats in operas by Handel, Mozart and Strauss, and as a sluttish, rambunctious Carmen. She is a fiercely expressive singer of baroque music, but has the lush allure required by Romantic composers such as Berlioz and Schumann. She dispenses Christian consolation as the angel in Elgar's Dream of Gerontius, yet also bites into the raucous nihilism of Kurt Weill. She once even sang an Australian Aboriginal lament in a piece by Peter Sculthorpe, droning as authentically as a didgeridoo.
Such versatility, however, can be a means of concealment: just who is von Otter when she's at home? Her new disc of songs by Benny Andersson, the founder-member of Abba, offers a startling glimpse of the truth. Von Otter, it turns out, is something of a rocker. She belts out "Money, Money, Money" with gutsy fervour, squeals as deliciously as Marilyn Monroe on "I Am Just a Girl", and triumphantly demonstrates that scatting is coloratura by other means.
Occasionally the mood is uproarious, but for the most part these are muted trips through a wistfully Nordic emotional landscape. "When All Is Said and Done" shivers as the leaves fall; "After the Rain" celebrates a reviving downpour and welcomes back the sun as spring begins. "The Day Before You Came" - the last Abba song, composed just before the group split up - becomes a psychodrama of quiet despair worthy of Sondheim. For once, von Otter is not just letting the music speak: it is she herself who is doing the talking, with touching, confessional intimacy.