She is the recipient of several Grammy Awards and has released a number of Edison Award-winning discs; she performs both opera and art song, and her repertoire spans Baroque to contemporary.
She has premiered more than twenty-five new works, notably Henri Dutilleux's song-cycle Correspondances, and has embraced several pieces created for her, including the Grawemeyer Award-winning opera L'Amour de Loin by Kaija Saariaho, The Great Gatsby by John Harbison, the nativity oratorio El Niño by John Adams, and Osvaldo Golijov's highly acclaimed chamber opera Ainadamar and song cycle Ayre.
In 2009, she premiered David Bruce's song cycle The North Wind was a Woman at the gala opening of the Chamber Music Society of the Lincoln Centre's season.
The BBC presented a prime-time telecast of her 1996 London Proms Concert, Dawn at Dusk, in which she performed songs from American musical theater.
She has worked with director Peter Sellars many times, including on his staging of Händel's Theodora at Glyndebourne, his Paris production of Stravinsky's The Rake's Progress—as part of the Los Angeles Philharmonic and Esa-Pekka Salonen's month-long residency at the Théâtre du Châtelet, 1996—a staging of Bach's cantata Mein Herze schwimmt im Blut, BWV 199, presented in the 1995–96 season at New York's 92nd Street Y, and the Salzburg Festival production of Olivier Messiaen's Saint François d'Assise (1998).
In 2011, she was the music director of the festival, where she performed the world premiere of the Peter Sellers-staged production of George Crumb's work Winds of Destiny.
In 2006, she founded the Graduate Vocal Arts Program at Bard College Conservatory in Annandale-on-Hudson, New York, serving as artistic director until 2019, when she was succeeded by Stephanie Blythe.