As well as performing alongside many of the world’s most renowned conductors and orchestras, she has had the privilege of working closely with many of today’s leading composers, including Matthias Pintscher, Olga Neuwirth, and Wolfgang Rihm. Several have written roles especially for her, including Peter Eötvos (Sierve Maria in Love and Other Demons), Pascal Dusapin (Prothoe in Penthesilea) and Marco Stroppa (Olbia in Il Re Orso). Her affinity for contemporary music has led to regular engagements with ensembles including Klangforum Wien, Ensemble Intercontemporain, International Contemporary Ensemble (ICE), Ensemble Remix and Ensemble Modern.
Although she has achieved success in a wide range of operatic repertoire, Montalvo is particularly associated with the title role of Berg’s Lulu. Following her debut in the part at the Opéra National de Paris, Le Monde described her performance as a true revelation: “The American soprano possesses real stage and vocal presence, and executes the exhausting role with incredible intensity”. Subsequently, Lulu has become the centerpiece of her stage work; she has performed it at houses including Deutsche Oper Berlin, Théâtre du Capitole Toulouse, Teatro de la Maestranza, Theater an der Wien, Komische Oper Berlin, and at Theater Basel, in the acclaimed production by Calixto Bieto.
Outside the opera house, Montalvo has a particularly close working relationship with Christoph Eschenbach, who has been both a mentor and a regular concert partner throughout her career. Since conducting her Carnegie Hall debut with the Philadelphia Orchestra, he has invited her to work with him alongside orchestras including the Vienna Philharmonic, the Houston Symphony, the London Philharmonic, the Munich Philharmonic and the Orchestre de Paris. Most recently, she performed the role of Sophie in a concert performance of Der Rosenkavalier with the National Symphony Orchestra under his baton at the Kennedy Center in Washington, DC.