The 200 khz bandwidth of an FM broadcast signal might have been narrowed to allocate more channels. It is wide enough to carry all that additional info such as

The 200 khz bandwidth of an FM broadcast signal might have been narrowed to allocate more channels. It is wide enough to carry all that additional info such as the stereo signal (not much of an issue in the 1940's, as nobody had stereo speakers or amplifiers at home), and the additional services (e.g. talking books for the blind, foreign language broadcasts, etc that have been multiplexed on top of the FM signal during the decades since). Now it also can carry the hierarchical digital (some of the comments to the original article apparently accept hierarchical-digital as high-definition, which it isn't) signals. The quality of music received by FM now is not so good as it used to be before all that other stuff started freeloading on the carrier. Most FM broadcast tuners and receivers are supposed to suppress the unwanted content by approximately 70 to 80 db. I don't know if the receivers go out of spec over the years, but when listening to classical music broadcasts medium loud, I often hear a soft garbled chatter during the quiet passages and silences between movements. From my POV, FM is fine for casual music listening but dead as a preferred medium for high-fidelity music. I am too discouraged by the poor S/N ratio that I now hear on FM to dare to spend much for for a better receiver that may not be significantly superior.