At the opening of the twentieth century the decisive influence of the ragtime pianists fell on white audiences tiring of the minstrel show and willing to pay to hear black performers. At the same time the American band was being heard everywhere, promoted by John Philip Sousa, the most successful musician of his time, and testifying among other things to pugnacious nationalism. Both phenomena would modulate into dance bands playing vigorous dance music. Burgeoning displays of sheet music in neighborhood stores, often music calling itself rag, attracted a diverse public, much of which never heard the concerts of the creators of ragtime. Modest as well as prosperous homes had a keyboard, either a piano or the less expensive reed organ: the industry built 107,000 harmoniums a year in 1900, and 177,000 pianos. By 1909, the figure was 364,000 pianos. Piano music was available beyond the proportion of the population that could play: by 1925, more than half the pianos produced were automatics, using player rolls for current hits (see Cyril Ehrlich, The Piano: a History). Such instruments, giving out more and better sound than the evolving phonograph had yet mastered, tuned the audience more closely than ever before to the latest fad in music.
A boom in social dancing began during the second decade of the twentieth century, along with the first recognition of music called jazz. Nat Shapiro quotes Variety as estimating that in the mid-1920s there were 60,000 dance bands playing on the dance floors of jazz age America. Beginning in 1920, radio broadcasting brought recorded and live music into homes, posing an economic challenge to pianos and combining with the Depression in 1929 to decimate record and phonograph sales. The music that America absorbed through these media came mostly from New York, from Tin Pan Alley publishing houses and from the flourishing Broadway stage, reproduced also in vaudeville houses across the country. When in the middle of the 1920s recording engineers developed microphones to replace recording horns, a new softer "crooning" performance became possible and stylish on records and over the radio.
Al Jolson's songs on screen in 1927 opened another medium. When the Depression crippled the New York musical theater, Hollywood studios became the patrons of much of professional songwriting, for the movies that were the country's largest entertainment indulgence during the 1930s. The record industry struggled back late in the decade, dominated by the big swing bands and their vocalists. As the war overtook the United States, a significant economic struggle surfaced in musical entertainment. The American Society of Composers, Authors, and Publishers ( ASCAP) had been formed in 1914 to collect performance royalties for the owners of song copyrights. By 1939 it held monopoly power over popular music performance, and a contract dispute with radio broadcasters led to the formation of Broadcast Music Incorporated (BMI) as a rival guild. Following a ten-month interval in 1941 during which no ASCAP music could be played on the radio, causing a boom in classical, folk, and public domain music generally, ASCAP entered into a new broadcast contract, but BMI continued and grew. BMI, growing out of the dispute where its rival stood for established interests, came to represent popular music from outside the New York-Hollywood establishment, and local markets compared with the network emphasis of ASCAP. An institution had appeared to reflect the regional, rural, and minority interests in the music world that would gain great audience support after the war.
When the war ended, the entertainment industry responded to the ready money of a new public, more urbanized, but less in touch with Broadway sophistication, and with expanding young families preparing to be the next generation of popular music consumers -- raised with unprecedented pocket money and leisure time and with an unsuspected susceptibility to the energies of rock and roll they would first hear in 1954. Carl Belz describes the recording industry in the years after the war as dividing its market in the interest of stability and consequently producing for the general market dull, or at least highly controlled and predictable, music. Small independent record companies sold to the country and Western and rhythm and blues markets, while the major companies guided the music of the largest pop market down a narrow channel, with a slow succession of new songs and much repetitive recording by competing stars.
Rock and roll, which the industry learned to ride to a staggering new sales volume, also jarred that industry into new patterns: new companies, new small-group recording economics, new audience definitions, and new relationships to radio broadcasting. Some of the story can be told in terms of technical innovations. Television as the surging home entertainment medium turned radio stations toward the disc jockey format of record programming. New sizes, speeds, and materials for the records themselves may have had wide implications. Belz makes an interesting analysis of the cultural meaning of the shift from 78 to 45 rpm records, as streamlining the experience of recorded music toward casualness, especially for young audiences, while their parents bought the more substantial 33 longplaying records that emerged at the same time in the early 1950s. The later movement of rock and its audience into long-playing records reflects the triumphing cultural and economic power of the same young generation, along with a growing seriousness and self-confidence of the makers of rock music.
The relationship of popular culture to ideology in the 1960s and into the 1970s has become of interest to academic sociology, although the alarmed interest of politicians has given way to accommodation. The relationship of the entertainment favored by highly visible classes of teenagers and young adults to the behavior of that audience, and especially its use of drugs, is probably now still too current an issue for full perspective and confident judgment. The history of popular music suggests that it is very unlikely that musical entertainment can induce new behavior, or even introduce new ideas to the audience it must court in order to sell itself. Though popular music has been blamed in the past for undermining community standards or otherwise damaging society, it is a new phenomenon for popular music to have the pervasive presence that prosperity and the portable radio and tape deck have given it lately, and for such conspicuous economic power to be vested in a youth audience. The history of popular music that is now happening cannot be fully schematized and managed by the patterns of earlier popular music. Its development has always been contingent, surprising, and even discontinuous except when we rationalize it with hindsight, and it is continuing that unpredictable development now.
As rock has evolved in the last quarter of a century and brought, among other things, self-conscious seriousness to popular music, it has prompted an immense volume of reportage and analysis, much of it empty but some perceptive and judicious. The attention that rock has demanded has occasioned the first widespread, serious critical attention to the popular arts in general. Nostalgia, publicity promotion, and the university environment of a part of the proprietary audience of rock have contributed to the growing critical and scholarly interest in popular music of the past as well as the present. We are in the process of discovering a heritage; it is certain to contribute to the understanding of our own culture.