On December 7, 1940, the Japanese attacked the U.S. naval base at Pearl Harbor, Hawaii, thus “waking the sleeping giant” and drawing the United States into World War II. Although those bombs at Pearl Harbor would be the only ones to fall on American soil during the conflict, the nation was shaken to its core. In the space of a few short years, everything would change, and those changes were reflected in the music.Like the forgotten artists of the 1920s, a lot of 1930s artists would be left behind. The swing bands would soar to success, becoming the soundtrack of the war years. By the end of the decade, though, the changes to society and a resurgent economy would make large orchestras a thing of the past, and new sounds would be given a chance to flourish.
Technology, which had advanced at a snail’s pace due to the Great Depression for much of the 1930s, was suddenly put into overdrive to feed the war effort. Recording technology would be radically affected by the limitations and technological advancements brought about by the war. With shellac in short supply, record manufacturers would switch to vinyl. Long-playing vinyl “microgroove” records had been experimented with by RCA Victor in the early 1930s, but were discontinued due to the Great Depression. After the war, they were reintroduced by Columbia as 12" records running at 33-1/3 rpm, while RCA Victor introduced 7" vinyl microgroove records running at 45 rpm. Although 10" 78 rpm records (now also made of vinyl) would remain popular for decades, the longer playing time of the new formats opened up new possibilities such as single-disc record albums. (The first albums in the late 1930s had been similar to photo albums: bound collections of sleeves holding individual 78 rpm records.)
Prior to the war, the Germans had invented another recording format: magnetic tape. After Germany was defeated, Americans developed their own uses for the technology, using it first for recording and eventually for consumer playback media.
Technology wasn’t the only cause of changes to American music during the war years, though; society was changing as well. By the end of the war, industrialization had caused a massive population shift from rural to urban areas, and along with this new life came a desire for new sounds, laying the groundwork for electric blues, honky tonk, and rock and roll.
One of the biggest influences on American music during this time, though, was caused not by the war or shifting demographics, but by a disagreement over royalties. In August 1942, a recording ban was put in place by the American Federation of Musicians (AFM), preventing many from recording until the strike ended in November 1944. While musicians could still play live shows or radio, the ban created a big gap both in the historical record and in the public consciousness. Because the ban applied only to instrumentalists, not vocalists, many record companies began recording vocal-only music as a way to skirt the issue. Whereas vocalists had always been an afterthought, this had the effect of making them the center of attention. By the time the ban was lifted, the paradigm had changed and big bands, while still popular for a while, would never again dominate the spotlight.
In October 1943, the AFM began allowing instrumentalists to record for special “V-discs,” which were only distributed to military personnel, not the general public. However, many instrumentalists were not captured on record at all during the strike, and so we have no window into the evolutionary process of their music. For example, after the ban ended, a new style of jazz called “bebop” would seemingly come out of nowhere. It had actually been a very organic extension of some trends in small-band swing music, but none of that process was ever recorded.
Like everything else in post-war America, bebop was a sign that nothing would ever be the same.