She appeared in most of the major opera houses in Europe through the 1940s and 1950s, including at La Scala (Jocasta in Oedipus rex by Stravinsky, and Ellen Orford in Peter Grimes), at the Teatro di San Carlo (Marie in Wozzeck which she also sang for the BBC in concert[1]), at the Royal Opera House Covent Garden (Mimi in La bohème), and at the festivals of Glyndebourne and Aix-en-Provence (Fiordiligi and Donna Elvira).
[3] Although her operatic repertoire was not large, it was notable for its stylistic range, from Mozart roles (Fiordiligi, Anna, Elvira, Cherubino and the Countess) to modern works by Berg, Britten and Stravinsky.
Her interpretation of Donna Anna in Don Giovanni under the direction Josef Krips is considered the standard for that opera.
Danco retired from singing in 1970 but remained active as a teacher, both at the Accademia Musicale Chigiana in Siena and as a regular visitor to the Britten-Pears School at Snape.
She also worked closely with Ernest Ansermet and the Suisse Romande Orchestra on a series of recordings in the 1950s, including Ravel's two one-act operas L'heure espagnole and L'enfant et les sortilèges, Debussy's Le martyre de Saint Sébastien, and Fauré's Requiem.