Of a musical family, de los Ángeles sang and played the guitar before studying piano and voice at the Conservatorio del Liceo in Barcelona. There she performed in concert and in 1945 made her opera debut as the Countess in Wolfgang Amadeus Mozart's Le nozze di Figaro. In 1947, after winning first prize in an international competition in Geneva, she gave concert and opera performances throughout Europe. In 1950 she had highly successful debuts at Covent Garden, London, as Mimi in Giacomo Puccini's La Bohème; at La Scala, Milan, in the title role of Richard Strauss's Ariadne auf Naxos; and at Carnegie Hall, New York City, in recital. Her debut at the Metropolitan Opera the following year was as Marguerite in Charles Gounod's Faust. De los Ángeles was an exceptionally versatile artist, and in the mid-1960s she limited her opera appearances and undertook many recital tours.