When it first appeared in the 1930s, FM radio was a technological marvel, providing better sound and nearly eliminating the static that plagued AM stations. It took another forty years, however, for FM's popularity to surpass that of AM. In Sounds of Change, Christopher Sterling and Michael Keith detail the history of FM, from its inception to its dominance (for now, at least) of the airwaves.
Initially, FM's identity as a separate service...