Deborah Voigt, Barbican, London

How many divas do you know who, having instructed the accompanist to move over, would play rather than sing her final encore? I'm not quite sure - in fact, I know - it's not what Deborah Voigt's adoring audience wanted (her piano-playing was nowhere near as finely nuanced as her singing). But by this stage of her celebrity recital at the Barbican Hall, she had earned the right to be a little cheeky. She had played her audience like a violin. Indeed, she might well have played one of those if it had been to hand.

Voigt has taken a little more than a decade (which is not much time at all) to establish herself at the very top of the operatic hierarchy. She is in the news now that the Royal Opera House has removed her from a forthcoming production because of her size. Hers is a big voice, an open voice, a voice with ample reach. She sings the lyric/dramatic repertoire; she sings Strauss and Wagner, the Italian spinto roles (Verdi in particular) and the heavyweight heroines. She and her excellent accompanist, Brian Zeger, pointedly set themselves well back on the platform. The message was clear: give this lady room.

Warming the voice took time. A set of Schubert songs, to be precise. This is not the repertoire we pay to hear Voigt sing. The penultimate line of her first song, "Auflösung", reads: "From every recess of my soul, gentle powers well up." Or maybe not so gentle. Her German, too, was not so hot to begin with. And that distinctive chest tone was asserting itself rather too readily, popping intrusively into focus with every dip into the lower register. The evenness of tone and exquisite sostenuto displayed by her pianist were marked by contrast.

But come the fanciful set of Zemlinsky songs - heady romances disguised as waltzes - Voigt was wearing her dramatic voice lightly, tossing off flights of coloratura fancy as though she were the Empress in Strauss's Die Frau ohne Schatten on an away-day to paradise. Then, Tchaikovsky; and Voigt wasn't just warmed up, but positively burning. Impassioned. The throat opened, the chords vibrated, the legato was deep, rich and even. In that great song "Ya li v pole da ne travushka byla?" ("Was I not a little blade of grass?") the sound was completely in style and character, each verse climaxing with an elaborate vocal cadenza on the words: "This must be my fate!" That one phrase alone left me craving to hear her Lisa in The Queen of Spades.

From home, Voigt brought quirky Charles Ives, in which the excited little girl at her first opera ("Memories") was the same little girl who wanted to play Fauré's Dolly Suite as her fourth encore. The warmth of her engagement with these homespun songs showed us the cosier side of Voigt - as did the heartfelt settings of Joyce, Keats and Hardy from her fellow American Ben Moore. I want to hear more of that composer.

And all of us wanted to hear more Strauss. This voice slips so naturally and without affectation into his phraseology. Voigt gave us four biggies and the inevitable "Zueignung" as her first encore. "Ich liebe dich" was both a declaration and a ringing endorsement of love, while in "Frühlingsfeier" ("Spring Ceremony") Voigt's cries of "Adonis! Adonis!" must have had them calling the fire brigade across the City of London. Terrific recital. World-class voice.