Josephine Antoinette Vadala was an American singer, singing voice specialist, and researcher. She was born on April 25, 1921, in Donora, Pennsylvania, USA. In her teens and early ’20s, Jo sang on the radio in Hollywood for the CBS radio network. In 1948, she married Thomas Estill, and in 1949 they had a daughter, Alice. Soon after, Jo embarked on a European solo concert tour in The Hague, Amsterdam, Copenhagen, Oslo, London, Zurich, Geneva, and Paris.
She returned to Colorado Springs, where until the mid-1960’s she continued to perform as a soloist with the Colorado Springs Chorale, Air Force Academy Chorus, Colorado Springs Symphony, and local churches.
In 1969 Jo earned a BA in Liberal Arts from Colorado College, where she was also on the voice faculty. She received a MA in Music Education in 1971 from Case Western Reserve University in Cleveland, Ohio. It was during this time that Jo minored in Speech and Hearing was introduced to voice science. In 1984, Jo graduated with a Ph.D. from the City University of New York.
Her research investigated voice qualities found in a range of singing styles, primarily “Sob,” “Twang,” “Speech,” “Opera,” and “Belt”. Estill used EMG, electroglottography, voice signal analysis, X-rays, laryngeal fiber endoscopy, acoustic measurements, and simultaneous video stroboscopy to understand what the vocal mechanism was doing while performing these voice qualities (models). The Estill Model identifies laryngeal and vocal tract configurations responsible for producing vocal sounds and resonance (voice qualities). In 1992, Jo founded ‘Estill Voice Training Systems LLC, which has a teacher certification program. Within the system, these models are used in exercises aimed at helping vocalists develop conscious, voluntary, and predictable control of the voice. Estill has impacted many voice teachers and professionals worldwide, including prominent voice teachers Gillyanne Kayes and Joan Lader.
Jo received an Honorary Doctorate, Doctor of Letters LittD, from the University of East Anglia. She was also named Honorary Associate of the Royal Academy of Music. In 2007, Jo was honored in Boulder, Colorado, at a gala performance by the ARS Nova Singers, an exceptional choir trained in the Estill Voice Model. In her later years, Jo resided in Santa Rosa, CA. She traveled internationally, giving seminars, and stayed active in voice research. Jo Estill died on December 9, 2010, in Santa Rosa, CA, of natural causes.