The possessor of a large-scaled, powerful dramatic soprano voice, joined to a vivid stage presence and finely tuned acting abilities, Jones enjoyed a lengthy international career that took her to all the world's major opera houses.

Her skills were cultivated through a long relationship with the Bayreuther Festspiele, through which she developed a more human, vulnerable, and womanly image for Richard Wagner's main female characters.

[1] Jones came to prominence in 1964 when she stood in for Leontyne Price as Leonora in Verdi's Il trovatore at the Royal Opera House, Covent Garden.

Her career then developed rapidly, and she met with success as Aïda, Leonore (in Fidelio), Desdemona (in Otello), Elisabeth (in Don Carlos), Donna Anna (in Don Giovanni), Cio-cio-san (in Madama Butterfly), Lady Macbeth (in Verdi's Macbeth), Santuzza (in Cavalleria rusticana), Octavian (in Der Rosenkavalier), Médée (in the Italian version) and Tosca.

Starting from the 1990s, other than the aforementioned parts, she went on to sing Widow Begbick (Mahagonny), Ortrud (in Lohengrin), the Woman in Arnold Schoenberg's Erwartung, the Kostelnicka (in Jenůfa), the Woman in Poulenc's La voix humaine, Ruth (in The Pirates of Penzance), Gertrud (in Hänsel und Gretel), the Kabanicha (in Káťa Kabanová), Herodias (in Salome) and Klytämnestra (in Elektra), the last five being mezzo-soprano roles.

[4] Jones made roles that exemplify the Wagnerian or heavy dramatic soprano fach, such as Brünnhilde, Isolde, Elektra, the Dyer's Wife and Turandot, part of her core repertoire, and performed them throughout the 1980s and 1990s.

[5] and Die Frau im Schatten – which are inspired by real historical characters, namely, Malvina Schnorr von Carolsfeld and Pauline de Ahna (wife of Richard Strauss).

In 2003, Jones made her debut as director and costume designer in a stage production of Der fliegende Holländer in Weimar, Germany.

In February 2008 she returned to the Mezzo-soprano repertoire singing the role of Herodias in Stephen Langridge's production of Richard Strauss' Salome at Malmö Opera in Sweden.

Jones makes a guest appearance in Quartet, a film by Dustin Hoffman, based on the comedy by Ronald Harwood about several retired opera singers planning to put on a concert to celebrate Verdi's birthday.