Her whole life was glowing testimony to its validity. A farm girl born in southern Sweden in 1918, she grew up pulling weeds and milking cows — things that she continued to do on visits home even after moving to Stockholm to study at the Royal Academy of Music and Opera School. As she tells it in “La Nilsson,” her autobiography that has just appeared in English, hers was a straightforward life marked by diligence and hard work, no matter what the task at hand. She describes a professional journey made with feet firmly on the ground.

It was a no-nonsense career that paid off handsomely with a stellar position in the opera world for four decades. Nilsson organizes the immense detail of her long career in chapters focused on the cities enriched by her talent: Stockholm, Vienna, Bayreuth, New York and Buenos Aires; a further chapter deals with Italy’s often disorganized opera houses and others with recordings and experiences with fans. An appreciation of her husband concludes the book.

She begins with her first “Tristan” at New York’s old Met in 1959 — long after her debut with America’s major companies. This series of Isoldes became legendary, when she sang opposite three indisposed tenors in a single performance: Karl Liebl, Ramon Vinay and Albert da Costa. (Each sang one act.) Nilsson has more to say about rehearsals than performances, and this gives the book an intimate feeling of opera from the inside.

Although a number of dressing-room events provide color, she eschews gossip; she even leaves the soprano for whom Wieland Wagner left wife and family unnamed. (It was Anna Silja.) She writes generously of colleagues, and among the conductors with whom she worked she speaks only of Herbert von Karajan with reserve. She calls her relationship with him “clouded.” She was irked not only by his vanity, but by the countless hours that he — doubling as director — spent on lighting rehearsals. She was unimpressed by Karajan’s conducting without score, for this left him unable to help singers who lost their place. (Prompters, she notes, were usually half asleep.) Relying upon a bit of farm metaphor, Nilsson portrays Karajan at a Vienna rehearsal “strutting about like a cock in a henhouse, his rear end stuck out and his head in the air.... It was exactly so.”

Although her career stands as a major chapter in the history of opera, Nilsson nonetheless lived between major musical epochs. In her early years she worked with such conductors as Erich Kleiber, Fritz Busch, Issai Dobrowen and Leo Blech, men firmly rooted in traditions that prevailed before the Second World War.

Both LP’s and CD’s were introduced after her debut, and she made the first complete recording of Wagner’s “Ring.” She retired — happily — just as Regieoper was about to crown the stage director king of opera. (It was the “Ring” project that allowed Nilsson — so to speak — to raise her voice together with her Scandinavian countrywoman and great predecessor in the Wagnerian Fach Kirsten Flagstad. Flagstad sang Fricka in “Das Rheingold”; Nilsson, Bru”nnhilde in the remaining three operas of the cycle. Although the two women never met, Flagstad sent Nilsson a “fan letter” after hearing her on a broadcast “Tristan” in 1959.)

Nilsson’s account of instruction at the Stockholm conservatory recalls Anna Russell’s statement that at one time or another her voice was “ruined by all the great teachers of the day.” For two years Nilsson worked with a man who insisted that she focus the full force of the voice on the vocal chords, which produced an intense tone — but without overtones and with tension that turned to pain. After another gripped her larynx and pressed it down — again causing pain — she fled to noted Wagnerian Nanny Larsen-Todsen, who spent lesson time telling of her own earlier life as “Queen of Bayreuth.” Happily, Nilsson had the intelligence and insight to work out problems of technique on her own.

Although she was noted for her sense of humor, few of the stories that circulated following Nilsson’s death on Christmas day 2006 have found their way into this book. (Two favorites: in her first Bayreuth “Siegfried” Wolfgang Windgassen, the eponymous hero, removed the sleeping Bru”nnhilde’s armor to find the tag from her hotel door on her bosom: “Please do not disturb! And when asked whether Joan Sutherland’s bouffant hair was real, Nilsson replied: “I don’t know; I haven’t pulled it. )

Her autobiography is thus without great excitement; careful consideration of assignments and thorough preparation kept disaster at bay. She married her first love, Bertil Niklasson, a veterinarian who later went into business on his own and frequently accompanied the soprano on her many trips abroad. And although she last sang in public in 1984 on a tour of West Germany with orchestra, she never spoke of retirement and loathed the term “farewell performance.” From 1983 to 1993 Nilsson — to great acclaim — taught master classes at New York’s Manhattan School of Music.

The mechanics of “La Nilsson” furrow the critical brow. This - strangely — is a translation from the German — not from the original Swedish. And although — says the translator in a brief preface — Nilsson saw the English text and liked it — or found it better at least than two others that she saw, one wonders why the English version is not based on the Swedish original.

The English version suggests — although this is no where said — that Nilsson wrote the text. Indeed, she concludes her introduction by speaking of “the blank sheet of paper to which I shall shortly entrust some of my memories.” But that’s probably a figure of speech, possibly from the “pen” of the translator. The Swedish original, on the other hand, says that Nilsson “narrated” the text to an unnamed scribe. In an earlier day the title page of such “autobiographes” commonly stated “as told to....” If the Nilsson opus is the product of this practice, the dictatee should somewhere be named.

The book contains two sections of photos and a detailed discography.

A personal recollection: I discovered Nilsson — as it were — on my own. In Vienna early in 1954 I heard her as Elsa in “Lohengrin” and the next evening as Elisabeth [correct] in “Tannhäuser.” Although I had not heard the name before — this was her first season singing outside Sweden — I knew immediately that this was the successor to Flagstad. I saw her “live” only once again and that was as the Dyer’s Wife in Strauss’ “Frau ohne Schatten” at the San Francisco Opera in 1981. (Also in that cast were Leonie Rysanek and James King — which caused wags to call it “an original-cast performance.”)

Trivia: Nilsson reports that the Vienna Philharmonic, pit orchestra in the State Opera, tunes almost half a step higher than A-440 Hertz to achieve a brighter sound. This — as Nilsson tells in her chapter “The Battle of the High Cs” — makes life even more difficult for singers.

Wes Blomster