Question: Which instrument is Clara Rockmore a virtuoso of in the novel Us Conductors?
Sentence (from "Us Conductors"): Published in 2014 by Random House in Canada and Tin House in the United States, the novel is a fictionalized account of the relationship between Léon Theremin (also known as Lev Termen), the inventor of the theremin, and Clara Rockmore, the musician regarded as the instrument's first virtuoso player.
Relevant evidence: No