Frere-Jones, Sasha (October 3, 2005). «Extraordinary Measures». New Yorker. «Apple's robust contralto, though sometimes heavy on vibrato, gave her line readings a pleasingly sinister feel.»
notablebiographies.com
«Fiona Apple». Notable Biographies. [Consulta: 5 setembre 2014].
«Fiona Apple with David Garza and Damien Rice». San Diego Arts. Arxivat de l'original el January 1, 2021. [Consulta: 15 febrer 2010]. Though most of her lyrics are sung in a straightforward pop contralto, she judiciously adds vibrato, sudden jumps into her head voice, and rapid reiterations of the same pitch (what academics in the classical music field call a "Monteverdi vibrato").[Enllaç no actiu]
«Fiona Apple with David Garza and Damien Rice». San Diego Arts. Arxivat de l'original el January 1, 2021. [Consulta: 15 febrer 2010]. Though most of her lyrics are sung in a straightforward pop contralto, she judiciously adds vibrato, sudden jumps into her head voice, and rapid reiterations of the same pitch (what academics in the classical music field call a "Monteverdi vibrato").[Enllaç no actiu]
