During the early 1950s, controversy arose regarding a supposed rivalry between Callas and Renata Tebaldi, an Italian lyrico spinto soprano renowned for the ravishing beauty of her voice. The contrast between Callas’s often unconventional vocal qualities and Tebaldi’s classically beautiful sound resurrected an argument as old as opera itself, namely, beauty of sound versus the expressive use of sound.
This “rivalry” reached a fever pitch in the mid-1950s, at times even engulfing the two women themselves, who were said by their more fanatical followers to have engaged in verbal barbs in each other’s direction. Tebaldi was quoted as saying, “I have one thing that Callas doesn’t have: a heart” while Callas was quoted in Time magazine as saying that comparing her with Tebaldi was like “comparing Champagne with Cognac. No, with Coca Cola.” However, witnesses to the interview stated that Callas only said “champagne with cognac”, and it was a bystander who quipped, “No, with Coca-Cola”, but the Time reporter attributed the latter comment to Callas.
The alleged rivalry aside, Callas made remarks appreciative of Tebaldi, and vice versa. During an interview with Norman Ross in Chicago, Callas said, “I admire Tebaldi’s tone; it’s beautiful—also some beautiful phrasing. Sometimes, I actually wish I had her voice.” Francis Robinson of the Met wrote of an incident in which Tebaldi asked him to recommend a recording of La Gioconda in order to help her learn the role. Being fully aware of the alleged rivalry, he recommended Zinka Milanov‘s version. A few days later, he went to visit Tebaldi, only to find her sitting by the speakers, listening intently to Callas’s recording. She then looked up at him and asked, “Why didn’t you tell me Maria’s was the best?”
This rivality was really building from the people of the newspapers and the fans. But I think it was very good for both of us, because the publicity was so big and it created a very big interest about me and Maria and was very good in the end. But I don’t know why they put this kind of rivality, because the voice was very different. She was really something unusual. And I remember that I was very young artist too, and I stayed near the radio every time that I know that there was something on radio by Maria.
Several singers have opined that the heavy roles undertaken in her early years damaged Callas’s voice. The mezzo-soprano Giulietta Simionato, Callas’s close friend and frequent colleague, stated that she told Callas that she felt that the early heavy roles led to a weakness in the diaphragm and subsequent difficulty in controlling the upper register.
Louise Caselotti, who worked with Callas in 1946 and 1947, prior to her Italian debut, felt that it was not the heavy roles that hurt Callas’s voice, but the lighter ones. Several singers have suggested that Callas’s heavy use of the chest voice led to stridency and unsteadiness with the high notes. In his book, Callas’s husband Meneghini wrote that Callas suffered an unusually early onset of menopause, which could have affected her voice. Soprano Carol Neblett once said, “A woman sings with her ovaries – you’re only as good as your hormones.”
Critic Henry Pleasants has stated that it was a loss of physical strength and breath-support that led to Callas’s vocal problems, saying,
Singing, and especially opera singing, requires physical strength. Without it, the singer’s respiratory functions can no longer support the steady emissions of breath essential to sustaining the production of focused tone. The breath escapes, but it is no longer the power behind the tone, or is only partially and intermittently . The result is a breathy sound—tolerable but hardly beautiful—when the singer sings lightly, and a voice spread and squally when under pressure.
In the same vein, Joan Sutherland, who heard Callas throughout the 1950s, said in a BBC interview,
[Hearing Callas in Norma in 1952] was a shock, a wonderful shock. You just got shivers up and down the spine. It was a bigger sound in those earlier performances, before she lost weight. I think she tried very hard to recreate the sort of “fatness” of the sound which she had when she was as fat as she was. But when she lost the weight, she couldn’t seem to sustain the great sound that she had made, and the body seemed to be too frail to support that sound that she was making. Oh, but it was oh so exciting. It was thrilling. I don’t think that anyone who heard Callas after 1955 really heard the Callas voice.
Michael Scott has proposed that Callas’s loss of strength and breath support was directly caused by her rapid and progressive weight-loss, something that was noted even in her prime. Of her 1958 recital in Chicago, Robert Detmer would write, “There were sounds fearfully uncontrolled, forced beyond the too-slim singer’s present capacity to support or sustain.”
Photos and videos of Callas during her heavy era show a very upright posture with the shoulders relaxed and held back. On all videos of Callas from the period after her weight loss, “we watch… the constantly sinking, depressed chest and hear the resulting deterioration”. This continual change in posture has been cited as visual proof of a progressive loss of breath support.
Commercial and bootleg recordings of Callas from the late 1940s to 1953—the period during which she sang the heaviest dramatic soprano roles—show no decline in the fabric of the voice, no loss in volume and no unsteadiness or shrinkage in the upper register. Of her December 1952 Lady Macbeth—coming after five years of singing the most strenuous dramatic soprano repertoire—Peter Dragadze would write for Opera, “Callas’s voice since last season has improved a great deal, the second passagio on the high B-Natural and C has now completely cleared, giving her an equally colored scale from top to bottom.” And of her performance of Medea a year later, John Ardoin writes, “The performance displays Callas in as secure and free a voice as she will be found at any point in her career. The many top B’s have a brilliant ring, and she handles the treacheroustessitura like an eager thoroughbred.”
In recordings from 1954 (immediately after her 80-pound weight loss) and thereafter, “not only would the instrument lose its warmth and become thin and acidulous, but the altitudinous passages would to her no longer come easily.” It is also at this time that unsteady top notes first begin to appear. Walter Legge, who produced nearly all of Callas’s EMI/Angel recordings, states that Callas “ran into a patch of vocal difficulties as early as 1954”: during the recording of La forza del destino, done immediately after the weight loss, the “wobble had become so pronounced” that he told Callas they “would have to give away seasickness pills with every side”. When asked whether he felt the weight loss affected Callas’s voice, Richard Bonynge stated, “I don’t feel it, I know it did. I heard her Norma in 1953, before she lost all that weight, and then again afterward, and the difference was incredible. Even more incredible was that the critics didn’t write about it. When Callas was at her best vocally, she was fat, but she got only a quarter of the recognition that she got after she had become thin and was a great star.” 
There were others, however, who felt that the voice had benefitted from the weight loss. Of her performance of Norma in Chicago in 1954, Claudia Cassidy would write, “there is a slight unsteadiness in some of the sustained upper notes. but to me her voice is more beautiful in color, more even through the range, than it used to be”. And at her performance of the same opera in London in 1957 (her first performance at Covent Garden after the weight loss), critics again felt her voice had changed for the better, that it had now supposedly become a more precise instrument, with a new focus. Many of her most critically acclaimed appearances are from the period 1954–1958 (Norma, La Traviata,Sonnambula and Lucia of 1955, Anna Bolena of 1957, Medea of 1958, to name a few).
Callas’s close friend and colleague Tito Gobbi thought that her vocal problems all stemmed from her state of mind:
I don’t think anything happened to her voice. I think she only lost confidence. She was at the top of a career that a human being could desire, and she felt enormous responsibility. She was obliged to give her best every night, and maybe she felt she wasn’t [able] any more, and she lost confidence. I think this was the beginning of the end of this career.
In support of Gobbi’s assertion, a bootleg recording of Callas rehearsing Beethoven‘s aria “Ah! Perfido” and parts of Verdi‘s La forza del destino shortly before her death shows her voice to be in much better shape than much of her 1960s recordings and far healthier than the 1970s concerts with Giuseppe Di Stefano.
Soprano Renée Fleming has stated that videos of Callas in the late 1950s and early 1960s reveal a posture that betrays breath-support problems:
I have a theory about what caused her vocal decline, but it’s more from watching her sing than from listening. I really think it was her weight loss that was so dramatic and so quick. It’s not the weight loss per se… But if one uses the weight for support, and then it’s suddenly gone and one doesn’t develop another musculature for support, it can be very hard on the voice. And you can’t estimate the toll that emotional turmoil will take as well. I was told, by somebody who knew her well, that the way Callas held her arms to her solar plexus [allowed her] to push and create some kind of support. If she were a soubrette, it would never have been an issue. But she was singing the most difficult repertoire, the stuff that requires the most stamina, the most strength.
Dramatic soprano Deborah Voigt, who lost 135 pounds after gastric bypass surgery, expressed similar thoughts concerning her own voice and body:
Much of what I did with my weight was very natural, vocally. Now I’ve got a different body—there’s not as much of me around. My diaphragm function, the way my throat feels, is not compromised in any way. But I do have to think about it more now. I have to remind myself to keep my ribs open. I have to remind myself, if my breath starts to stack. When I took a breath before, the weight would kick in and give it that extra Whhoomf! Now it doesn’t do that. If I don’t remember to get rid of the old air and re-engage the muscles, the breath starts stacking, and that’s when you can’t get your phrase, you crack high notes.
Callas herself attributed her problems to a loss of confidence brought about by a loss of breath support, even though she does not make the connection between her weight and her breath support. In an April 1977 interview with journalist Philippe Caloni, she stated,
“My best recordings were made when I was skinny, and I say skinny, not slim, because I worked a lot and couldn’t gain weight back; I became even too skinny. . . I had my greatest successes–Lucia, Sonnambula, Medea, Anna Bolena–when I was skinny as a nail. Even for my first time here in Paris in 1958 when the show was broadcast through Eurovision, I was skinny. Really skinny.” 
And shortly before her death, Callas confided her own thoughts on her vocal problems to Peter Dragadze:
I never lost my voice, but I lost strength in my diaphragm. … Because of those organic complaints, I lost my courage and boldness. My vocal cords were and still are in excellent condition, but my ‘sound boxes’ have not been working well even though I have been to all the doctors. The result was that I overstrained my voice, and that caused it to wobble. (Gente, October 1, 1977)
Whether Callas’s vocal decline was due to ill health, early menopause, over-use and abuse of her voice, loss of breath-support, loss of confidence, or weight loss will continue to be debated. Whatever the cause may have been, her singing career was effectively over by age 40, and even at the time of her death at age 53, according to Walter Legge, “she ought still to have been singing magnificently”.
The latter half of Callas’s career was marked by a number of scandals. During performances of Madama Butterfly in Chicago, Callas was confronted by a process server who handed her papers about a lawsuit brought by Eddy Bagarozy, who claimed he was her agent. Callas was photographed with her mouth turned in a furious snarl. The photo was sent around the world and gave rise to the myth of Callas as a temperamental prima donna and a “Tigress”. In 1956, just before her debut at the Metropolitan Opera, Time ran a damaging cover story about Callas, with special attention paid to her difficult relationship with her mother and some unpleasant exchanges between the two.
In 1957, Callas was starring as Amina in La sonnambula at the Edinburgh International Festival with the forces of La Scala. Her contract was for four performances, but due to the great success of the series, La Scala decided to put on a fifth performance. Callas told the La Scala officials that she was physically exhausted and that she had already committed to a previous engagement, a party thrown for her by her friendElsa Maxwell in Venice. Despite this, La Scala announced a fifth performance, with Callas billed as Amina. Callas refused to stay and went on to Venice. Despite the fact that she had fulfilled her contract, she was accused of walking out on La Scala and the festival. La Scala officials did not defend Callas or inform the press that the additional performance was not approved by Callas. Renata Scotto took over the part, which was the start of her international career.
In January 1958, Callas was to open the Rome Opera House season with Norma, with Italy’s president in attendance. The day before the opening night, Callas alerted the management that she was not well and that they should have a standby ready. She was told “No one can double Callas”. After being treated by doctors, she felt better on the day of performance and decided to go ahead with the opera. A survived bootleg recording of the first act reveals Callas sounding ill. Feeling that her voice was slipping away, she felt that she could not complete the performance, and consequently, she cancelled after the first act. She was accused of walking out on the president of Italy in a fit of temperament, and pandemonium broke out. Press coverage aggravated the situation. A newsreel included file footage of Callas from 1955 sounding well, intimating the footage was of rehearsals for the Rome Norma, with the voiceover narration, “Here she is in rehearsal, sounding perfectly healthy”, followed by “If you want to hear Callas, don’t get all dressed up. Just go to a rehearsal; she usually stays to the end of those.” The scandal became notorious as the “Rome Walkout”. Callas brought a lawsuit against the Rome Opera House, but by the time the case was settled thirteen years later and the Rome Opera was found to be at fault for having refused to provide an understudy, Callas’s career was already over.
Callas’s relationship with La Scala had also started to become strained after the Edinburgh incident, and this effectively severed her major ties with her artistic home. Later in 1958, Callas and Rudolf Bing were in discussion about her season at the Met. She was scheduled to perform in Verdi’s La traviata and in Macbeth, two very different operas which almost require totally different singers. Callas and the Met could not reach an agreement, and before the opening of Medea in Dallas, Bing sent a telegram to Callas terminating her contract. Headlines of “Bing Fires Callas” appeared in newspapers around the world. Maestro Nicola Rescigno later recalled, “That night, she came to the theater, looking like an empress: she wore an ermine thing that draped to the floor, and she had every piece of jewellery she ever owned. And she said, ‘You all know what’s happened. Tonight, for me, is a very difficult night, and I will need the help of every one of you.’ Well, she proceeded to give a performance [of Medea] that was historical.”
Bing would later say that Callas was the most difficult artist he ever worked with, “because she was so much more intelligent. Other artists, you could get around. But Callas you could not get around. She knew exactly what she wanted, and why she wanted it.” Despite this, Bing’s admiration for Callas never wavered, and in September 1959, he sneaked into La Scala in order to listen to Callas record La Gioconda for EMI. Callas and Bing reconciled in the mid 1960s, and Callas returned to the Met for two performances of Tosca with her friend Tito Gobbi.
In her final years as a singer, she sang in Medea, Norma, and Tosca, most notably her Paris, New York, and London Toscas of January–February 1964, and her last performance on stage, on July 5, 1965, at Covent Garden. A television film of Act 2 of the Covent Garden Tosca of 1964 was broadcast in Britain on February 9, 1964, giving a rare view of Callas in performance and, specifically, of her on-stage collaboration with Tito Gobbi.
In 1969, the Italian filmmaker Pier Paolo Pasolini cast Callas in her only non-operatic acting role, as the Greek mythological character of Medea, in his film by that name. The production was grueling, and according to the account in Ardoin’s Callas, the Art and the Life, Callas is said to have fainted after a day of strenuous running back and forth on a mudflat in the sun. The film was not a commercial success, but as Callas’s only film appearance, it documents her stage presence.
From October 1971 to March 1972, Callas gave a series of master classes at the Juilliard School in New York. These classes later formed the basis of Terrence McNally‘s 1995 play Master Class. Callas staged a series of joint recitals in Europe in 1973 and in the U.S., South Korea, and Japan in 1974 with the tenor Giuseppe Di Stefano. Critically, this was a musical disaster owing to both performers’ worn-out voices. However, the tour was an enormous popular success. Audiences thronged to hear the two performers, who had so often appeared together in their prime. Her final public performance was on November 11, 1974, in Sapporo, Japan.
In 1957, while still married to husband Giovanni Battista Meneghini, Callas was introduced to Greek shipping magnate Aristotle Onassis at a party given in her honour by Elsa Maxwell after a performance in Donizetti‘s Anna Bolena. The affair that followed received much publicity in the popular press, and in November 1959, Callas left her husband. Michael Scott asserts that Onassis was not why Callas largely abandoned her career, but that he offered her a way out of a career that was made increasingly difficult by scandals and by vocal resources that were diminishing at an alarming rate. Franco Zeffirelli, on the other hand, recalls asking Callas in 1963 why she had not practiced her singing, and Callas responding that “I have been trying to fulfill my life as a woman.” According to one of her biographers, Nicholas Gage, Callas and Onassis had a child, a boy, who died hours after he was born on March 30, 1960. In his book about his wife, Meneghini states categorically that Maria Callas was unable to bear children. As well, various sources dismiss Gage’s claim, as they note that the birth certificates Gage used to prove this “secret child” were issued in 1998, twenty-one years after Callas’s death. Still other sources claim that Callas had at least one abortion while involved with Onassis. In 1966, Callas renounced her U.S. citizenship at the American Embassy in Paris, to facilitate the end of her marriage to Meneghini. The relationship ended two years later in 1968, when Onassis left Callas in favour of Jacqueline Kennedy. However, the Onassis family’s private secretary, Kiki, writes in her memoir that even while Aristotle was with Jackie, he frequently met up with Maria in Paris, where they resumed what had now become a clandestine affair.
Callas spent her last years living largely in isolation in Paris and died at age 53 on September 16, 1977, of aheart attack. A funerary liturgy was held at Agios Stephanos (St. Stephen’s) Greek Orthodox Cathedral on rue Georges-Bizet, Paris, on September 20, 1977, and her ashes were interred at the Père Lachaise Cemetery. After being stolen and later recovered, in the spring of 1979 they were scattered over the Aegean Sea, off the coast of Greece, according to her wish.
During a 1978 interview, upon being asked “Was it worth it to Maria Callas? She was a lonely, unhappy, often difficult woman,” music critic and Callas’s friend John Ardoin replied,
That is such a difficult question. There are times when certain people are blessed—and cursed—with an extraordinary gift, in which the gift is almost greater than the human being. Callas was one of these people. It was as if her own wishes, her life, her own happiness were all subservient to this incredible, incredible gift that she was given, this gift that reached out and taught us things about music that we knew very well, but showed us new things, things we never thought about, new possibilities. I think that is why singers admire her so. I think that’s why conductors admire her so. I know it’s why I admire her so. And she paid a tremendously difficult and expensive price for this career. I don’t think she always understood what she did or why she did it. She usually had a tremendous effect on audiences and on people. But it was not something she could always live with gracefully or happily. I once said to her “It must be a very enviable thing to be Maria Callas.” And she said, “No, it’s a very terrible thing to be Maria Callas, because it’s a question of trying to understand something you can never really understand.” She couldn’t really explain what she did. It was all done by instinct. It was something embedded deep within her.
All recordings are in mono unless otherwise indicated. Live performances are typically available on multiple labels.
- Verdi, Nabucco, conducted by Vittorio Gui, live performance, Napoli, 20 December 1949
- Verdi, Il trovatore, conducted by Guido Picco, live performance, Mexico City, June 20, 1950
- Verdi, Aida, conducted by Oliviero De Fabritiis, live performance, Palacio de Bellas Artes, Mexico City, July 3, 1951
- Ponchielli, La Gioconda, conducted by Antonino Votto, studio recording for Fonit Cetra, September 1952
- Bellini, Norma, conducted by Vittorio Gui, live performance, Covent Garden, London, November 18, 1952
- Verdi, Macbeth, conducted by Victor de Sabata, live performance, La Scala, Milan, December 7, 1952
- Bellini, I puritani, conducted by Tullio Serafin, studio recording for EMI, March–April 1953
- Mascagni, Cavalleria rusticana, conducted by Tullio Serafin, studio recording for EMI, August 1953
- Puccini, Tosca, conducted by Victor de Sabata, studio recording for EMI, August 1953.
- Verdi, La traviata, conducted by Gabriele Santini, studio recording for Fonit Cetra, September 1953
- Cherubini, Medea, conducted by Leonard Bernstein, live performance, La Scala, Milan, December 10, 1953
- Leoncavallo, Pagliacci, conducted by Tullio Serafin, studio recording for EMI, June 1954
- Spontini, La vestale, conducted by Antonino Votto, live performance, La Scala, Milan, December 7, 1954
- Verdi, La traviata, conducted by Carlo Maria Giulini, live performance, La Scala, Milan, May 28, 1955
- Puccini, Madama Butterfly, conducted by Herbert von Karajan, studio recording for EMI, August 1955
- Verdi, Aida, conducted by Tullio Serafin, studio recording for EMI, August 1955
- Verdi, Rigoletto, conducted by Tullio Serafin, studio recording for EMI, September 1955
- Donizetti, Lucia di Lammermoor, conducted by Herbert von Karajan, live performance, Berlin, September 29, 1955
- Bellini, Norma, conducted by Antonino Votto, live performance, La Scala, Milan, December 7, 1955.
- Verdi, Il trovatore, conducted by Herbert von Karajan, studio recording for EMI, August 1956
- Puccini, La bohème, conducted by Antonino Votto, studio recording for EMI, August–September 1956. Like her later recording of Carmen, this was her only performance of the complete opera, as she never appeared onstage in it.
- Verdi, Un ballo in maschera, conducted by Antonino Votto, studio recording for EMI, September 1956
- Rossini, The Barber of Seville, conducted by Alceo Galliera, studio recording for EMI in stereo, February 1957
- Bellini, La sonnambula, conducted by Antonino Votto, studio recording for EMI, March 1957
- Donizetti, Anna Bolena, conducted by Gianandrea Gavazzeni, live performance, La Scala, Milan, April 14, 1957
- Bellini, La sonnambula, conducted by Antonino Votto, live performance, Cologne, July 4, 1957
- Puccini, Turandot, conducted by Tullio Serafin, studio recording for EMI, July 1957
- Cherubini, Medea, conducted by Tullio Serafin, studio recording for Ricordi in stereo, September 1957
- Verdi, Un ballo in maschera, conducted by Gianandrea Gavazzeni, live performance, La Scala, Milan, December 7, 1957
- Verdi, La traviata, conducted by Franco Ghione, live performance, Lisbon, March 27, 1958
- Mad Scenes (excerpts from Anna Bolena, Bellini’s Il pirata and Ambroise Thomas‘s Hamlet), conducted by Nicola Rescigno, studio recording for EMI in stereo, September 1958
- Cherubini, Medea conducted by Nicola Rescigno, live performance at the Dallas Civic Opera in 1958; considered to be Callas’s most notable performance of Cherubini’s opera.
- Ponchielli, La Gioconda, conducted by Antonino Votto, studio recording for EMI in stereo, September 1959
- Puccini, Tosca, conducted by Carlo Felice Cillario, live performance, London, January 1964
- Bizet, Carmen, conducted by Georges Prêtre, studio recording for EMI in stereo, 1964. It is her only performance of the role, and her only performance of the complete opera; she never appeared in it onstage. The recording used the recitatives added after Bizet’s death. Callas’s performance caused critic Harold C. Schonberg to speculate in his book The Glorious Ones that Callas perhaps should have sung mezzo roles instead of simply soprano ones.
- Puccini, Tosca, conducted by Georges Prêtre, studio recording for EMI in stereo, December 1964.
Sources: YouTube, Wikipedia, Mariacallas.com, IMDB, NMDB