^ abvon Bernewitz, Robert (February 16, 2016). "Ron Anderson - An interview with the vocal coach to the stars". Musicguy247. Retrieved March 21, 2021. Prior to World War II, Fritz Zweig was one of the premier operatic directors and conductors in Europe. His wife, whose stage name was Tilly DeGarmo, was one of the most celebrated German sopranos of the era...Mrs. Zweig taught me the mechanics of vocalization and the fundamentals of breath management, vocal placement, vowel modification and diction. She also taught me German, French, and Italian, which are essential languages for every professional opera singer.
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^Dearmore, Kelly (May 29, 2014). "Tom Keifer of Cinderella: 'Singing is Very Much a Mental Thing'". Dallas Observer. Retrieved March 21, 2021. In 2009, I met vocal coach Ron Anderson, and he really put it all together for me, and I've been using his techniques ever since. I've done three Cinderella tours and I'm now on my second tour for the solo record since I worked with Anderson, and my voice is as reliable as it's ever been.