Obituary: Barbara Thornton

BARBARA THORNTON will be best remembered through the medieval-music group Sequentia, which she founded in 1977 with Benjamin Bagby, her partner in music as in life, and in particular through her best-selling recordings of the 12th-century mystic Hildegard of Bingen. Those discs took Thornton's music-making into hundreds of thousands of homes.

Thornton was born in New Jersey and studied at Sarah Lawrence College, graduating in 1972, and it was while she was on a tour with the Sarah Lawrence European Chorus that she decided to stay on in Europe and study music. To begin with, she continued her vocal training in Amsterdam before going on to operatic studies in Zurich and Italy. All the while, her interest in medieval music was growing, ultimately becoming too strong to resist, and in 1974 she moved to Basel and the Schola Cantorum Basiliensis, where three years later she was awarded an advanced degree in performance practice.

The founding of Sequentia at the end of her studies was a bold move that was to be crowned with then unimaginable success. Sequentia was typical of a number of early-music groups which came to the fore in the 1980s in combining exacting standards of performance that was based on scholarship no less painstaking in its execution.

That approach was to characterise Thornton's approach to a range of different composers and schools which outsiders tend to lump together under the blanket categorisation of "medieval music" - through Sequentia Thornton was concerned both to establish the individuality of the music she was performing and also to bring it to her audiences not as some museum piece but as a living experience, to be witnessed as a performance might have been almost a thousand years ago.

Sequentia's involvement with the music of Hildegard of Bingen - abbess, composer, poet, correspondent of popes and kings, "the Sybil of the Rhine" - began in 1981, a year before the release of the Hyperion recording A Feather on the Breath of God, by Christopher Page and his Gothic Voices, which is generally credited with having started the current revival of interest in Hildegard, who has meantime become something close to a new-age icon.

Sequentia first recorded Hildegard's Ordo Virtutum, her only stage work and perhaps the first music-drama (it tells of the temptation of a soul by the devil), in the early 1980s and went on to record her entire output, culminating this year in a re-recording of the Ordo Virtutum, now informed by everything Thornton and her fellow musicians had learned in the interim.

But Sequentia's explorations were not confined to the music of Hildegard. Thornton's discography embraces music from the School of Notre Dame and the courtly love-songs of northern France, from the 12th and 13th centuries, motets and chansons by the early-14th-century Philippe de Vitry, songs and ballads by his Austrian contemporary Oswald von Wolkenstein, one of the last of the Minnesingers, as well as an extensive examination of music from early Spanish sources.

Barbara Thornton's voice was an important element in Sequentia's success. Andrew Porter wrote in The New Yorker that she had "one of the most beautiful sopranos - strong, and pure, and passionate - that I have heard in a long time". Other critics variously described her as having "a tone as focused and intense as a medieval reed instrument", sounding "like a divine messenger of absolute truth".

The American musicologist Paul Attinello found her stage presence to be:

frankly amazing. A calm woman, rather plain, but as ruthlessly confident as an army with banners, who took the stage with an unquestionable completeness that I don't remember seeing anywhere else . . . At one point she was singing a long (and I mean long) strophic monody which in anyone else's hands would have been terminally boring, and I remember thinking: I could listen to her do that all night . . . It was sort of as though she wasn't singing for us, the audience, but past us to something or someone much more important - the composer perhaps, or history, or God, I couldn't say what. And we were extremely privileged to eavesdrop.

In this 900th year of the birth of Hildegard of Bingen, Sequentia have been touring the Ordo Virtutum in Europe and North America, bringing it to the Proms early in September - but without Thornton, whose last stage appearance was in July, at the Lincoln Center in New York. She was already suffering from the brain tumour that was to cut short a career of distinction, and continued promise, at the age of 48.

Barbara Thornton, singer and musicologist: born Summit, New Jersey 6 January 1950; died Cologne, Germany 8 November 1998.