On Christmas Day 1931 the Metropolitan Opera in New York broadcast a full live opera for the first time in its history. The Saturday broadcast from the Met was a resounding hit and would quickly become a permanent part of American musical culture. The Met had considered broadcasts before the historic day. In 1909 a microphone had been placed on the Met stage for a few numbers from Tosca sung by Enrico Caruso and Emmy Destinn. The few amateur radio pioneers involved had concluded that "insurmountable obstacles would keep opera off of the radio." Twenty-two years later, with the Met surrounded by rumors of financial ruin brought on by the Depression, the NBC broadcast of Engelbert Humperdinck's Hansel and Gretel reached millions of listeners from coast to coast in the United States and was picked up by stations in Japan and...