[5] After a very successful concert in New York in 1979 she established herself at the Metropolitan Opera, starting in 1981 as Nightingale in L'Enfant et les sortilèges (Ravel) and continuing for the next nine seasons singing such roles as Fiakermilli in Arabella, Blondchen in Die Entführung aus dem Serail, Zerbinetta in Ariadne auf Naxos, Olympia in Les contes d'Hoffmann,[6] the title role of Stravinsky's Le Rossignol, Clara in Porgy and Bess and especially as Gilda in Rigoletto.

Bradley was a frequent guest on the stage of the Los Angeles Opera as Oscar, Blondchen, Zerbinetta, Romilda, Zerlina, and in the 1997-98 season as Pamina in Die Zauberflöte.

With her bell like voice, she was successful not only in female roles such as Gilda, Susanna, Nannetta, Sophie or Pamina but also the pert Blondchen, as capricious Zerbinetta and Musetta or the androgynous Oscar.

Her concert repertoire encompasses important works from the Baroque to the 20th century and as a recitalist she performed in Paris, Tokyo, Lisbon, San Sebastian, Los Angeles and New York.

During her stay she was honored on 5 July 2014 with a 'sun', a commemorative bronze plaque embedded in the Star's Promenade (similar to the Hollywood Walk of Fame)[17] which is located in front of the Sanatorium Marconi in the Spa Park.