[7] She performed regularly at the Théâtre du Châtelet and participated in multiple recordings including Offenbach's operetta La belle Hélène, staged by French director Laurent Pelly.
She came to international attention singing Erda[10] and Waltraute in Wagner's Der Ring des Nibelungen conducted by Simone Young and directed by Claus Guth[11] between 2008 and 2010.
Dramatic roles include Fricka in Das Rheingold and Die Walküre,[12] Klytamnestra in Elektra,[13] Amneris in Aida, Ulrica in Un ballo in maschera, Branngäne in Tristan und Isolde, Lucretia in The Rape of Lucretia, Mescalina in Le Grand Macabre, Judith in Bluebeard's Castle, Baba the Turk in The Rake's Progress, the title role in Carmen and Dalilah in Samson et Dalilah.
Humble has sung most of the major mezzo concert repertoire including the Waldtaube in Schoenberg's Gurre-Lieder,[14] Verdi's Requiem, Handel's Messiah, Mahler Symphonies No.
8, Elgar's Sea Pictures, Wagner's Wesendonck Lieder, Dvorák's Requiem, Elgar's The Music Makers, The Dream of Gerontius with conductors such as Simone Young, Asher Fisch, Richard Hickox, Andris Nelsons, Pietari Inkinen, Vladimir Ashkenazy, Claudio Abbado, Jaap van Zweden, Edo de Waart, Gianluigi Gelmetti and Peter Schneider.