Dame Elisabeth Schwarzkopf, who has died aged 90, was one of the most distinguished and influential singers of the 20th century, rightly described by her husband, the record producer Walter Legge, as a "bloody marvel" days before his death when - already in her 60s - she was giving a recital in Zurich. The pristine beauty of her lyric soprano and the charm of her person, combined with hard work and innate intelligence, lent her performances a compelling authority, even though some, not unjustly, considered that artifice sometimes replaced art in her interpretations of both opera and lieder. But in these fields, she gained extraordinary acclaim over two-and-a-half decades.
From the outset of her career she divided her time between the operatic stage and the concert platform, becoming equally adept in both worlds. Her opera repertory latterly concentrated for the most part on Mozart and Richard Strauss. She became the leading exponent of lieder among female singers of her generation, on a par with the achievement of her male counterpart, Dietrich Fischer-Dieskau, with whom she often appeared in concert. Like him, she sang a far larger and more ambitious repertory of song than any of their predecessors, taking advantage of the long-playing record's appearance to commit to disc a vast quantity of material. Schwarzkopf devoted much attention to Hugo Wolf, of whom Legge was particularly fond. Indeed, his long and strict sessions coaching her in Wolf have become the stuff of legends.
She was at her very best in choral works. Her Bach, as evinced in her recordings of that composer, was impeccable in voice and style. She floated the soprano solo of Brahms's Ein Deutsches Requiem with calm loveliness. Only in the Verdi Requiem did she seem a shade out of her element. On stage, Schwarzkopf lent her strong, often affecting personality to very specific roles. She was, in Mozart, a gracious Countess Almaviva (Le Nozze di Figaro; though she had started out as Susanna, she moved to the Countess at the Salzburg Festival in 1949), a formidable Fiordiligi (Cosi Fan Tutte), whose vocal histrionics never fazed her, and an emotionally overwrought Donna Elvira (Don Giovanni), her characterisations always seconded by her technical skill. In Strauss, she was a mercurial Marschallin in Der Rosenkavalier, a little artificial for some tastes (a 1962 Salzburg film is extant), and a witty Countess Madeleine in Capriccio, the composer's operatic swansong.
Eventually she confined herself to these parts, but earlier in her career her repertory was far more extensive. At the Berlin Städtische Oper, which she joined in 1938, she was famed for her soubrette roles - Adele (Die Fledermaus), Musetta (La Bohème) and the immensely taxing Zerbinetta (Ariadne auf Naxos) among them. When she moved to the Vienna State Opera, from which her international fame derived, in 1942, her debut role was Rosina (Il Barbiere di Siviglia), still in the soubrette area, but by the time the war was over and the State Opera made its famous visit to Covent Garden in 1947, she had graduated to Marzelline in Fidelio and Donna Elvira. Both made a distinct impression - so much so that she was asked to join the nascent Covent Garden Opera Company for whom, between 1947 and 1952, she sang, all in English, not only Pamina (Magic Flute), Susanne, Eva (Mastersingers), Sophie (her earlier part in Der Rosenkavalier) from the German repertory, but also Violetta (La Traviata), Gilda (Rigoletto), Mimi (La Bohème), Butterfly and Massenet's Manon, an extraordinary achievement both for its range and for the fact that she was singing in a foreign language.
It was at about this time Legge became interested in her both musically and personally, although he later realised that she had been in the chorus when he recorded The Magic Flute with Sir Thomas Beecham in Berlin in 1938. He later commented: "I didn't even notice her - I must have been blind!"
The pair were married in 1953, and after that he became a profound influence on her career. As Legge was one of EMI's two chief producers, Schwarzkopf had an open sesame to make virtually as many recordings as she liked. From the era of 78rpm discs until 1964, when Legge left EMI, they collaborated on an unprecedently long catalogue of recordings, among the most successful of which were many sets of operetta, to whose heroines Schwarzkopf's style was peculiarly well suited. Die Fledermaus and The Merry Widow, both conducted by Herbert von Karajan, were among the most successful. Karajan was also in charge of one of Schwarzkopf's three recordings of Richard Strauss's Four Last Songs, a live event at the Festival Hall, but probably the best of the three is the earliest, a 1953 studio performance under Otto Ackermann, the voice at its freshest, her style at its most natural.
In 1951, Schwarzkopf created the role of Anne Trulove in Stravinsky's The Rake's Progress, at the Fenice in Venice (of which there exists an off-the-air recording). The same year she made her only Bayreuth appearances - at the reopening of the house in Beethoven's Choral Symphony under Wilhelm Furtwängler, whom she greatly revered, and as Eva under Karajan. Both events were recorded by Legge for posterity, and show her at her most persuasive. Her main appearances in the US were with the San Francisco Opera, where she appeared from 1955 (debut as the Marschallin) to 1964. Her Metropolitan debut was belatedly made in 1963, again as the Marschallin, and she returned as Donna Elvira the following year.
Schwarzkopf was born in Jarocin, now in Poland, south east of Poznan; at the time of her birth, it was in eastern Germany and known as Jarotschin. The highly educated daughter of a classics master, she entered the Berlin Hochschule für Musik in 1934, studying at first with Lula Mysz-Gmeiner, a celebrated lieder interpreter. However, Schwarzkopf claimed she learnt much more from Maria Ivogün, who in her own career shared much of her pupil's early coloratura repertory.
Schwarzkopf gained her first knowledge of lieder from Ivogün and from Ivogün's second husband, accompanist Michael Raucheisen, who recruited Schwarzkopf for his ambitious wartime project of recording whole swathes of the lieder repertory. These were preserved on early tape, and issued later on disc. They show Schwarzkopf's voice in its youthful prime.
At the same time, Raucheisen partnered her in her first lieder recital, in the Beethoven Saal, Berlin, in 1942. At this time, the singer reportedly had connections with the Nazis, revealed in a controversial biography that appeared in 1996. The revelations, denied by her, caused a considerable stir. The truth is that as an attractive and impressionable young singer, she inevitably sought favour with the powers that be. The political affiliation probably went no further than that. At war's end she was active in Vienna, apparently with no stain on her character.
Schwarzkopf virtually gave up her career when Legge died in 1979. In any case she had probably gone on singing, at his behest, a few years too long. The pair had begun giving master classes. After his death she continued them on her own and in his memory. Several of her pupils on these occasions were distressed that she was so intent on giving them minute instructions on interpretation that they lost confidence in themselves. Undoubtedly she was all too keen to pass on to them all she had learnt in her long years on the recital platform. Similar single-mindedness came into play in her celebrated appearance on Desert Island Discs, in which all eight of her discs were of performances by herself.
Great care over detail, almost to a fault, was always the hallmark of her own performances. They were part and parcel of her concern to communicate her feelings about the piece in hand to her audiences. Any reservation on that account pales before the poise and musicianship of her readings. Nowhere was that more self-evident than in her recording of Wagner's song Träume, which she chose to have played at Legge's memorial service. The hushed intimacy and emotional charge was a tribute to all he had done to make her the individual artist she became.
She was made a doctor of music by Cambridge University in 1976, and became a DBE in 1992.
· Olga Maria Elisabeth Friederike Schwarzkopf, soprano, born December 9 1915; died August 3 2006.