The arrival of the airplay chart was front-page news in Billboard. The headline roared: "Jockeys' First Platter Tab." And in the story, Billboard declared, "...the survey was made in conjunction with the disc jockeys of the nation, with the pancake flippers telling their all."

The airplay chart completed the triad of mainstream music popularity charts. But Billboard also recognized music popularity in other categories. The first chart of black music was introduced in the Oct. 24, 1942, issue under the name "Harlem Hit Parade." In 1948, a retail chart was introduced with the name "Best Selling Retail Race Records." Some on the magazine feared that the terminology might be offensive. It was at precisely that moment that Billboard coined the term "rhythm & blues" and in late June 1949 changed the "Race Records" rankings to "Best Selling Retail Rhythm & Blues Records." Jerry Wexler, an editor who would leave Billboard to become a founding partner in Atlantic Records, is generally credited with this coinage.

Country music also had its own charts. The initial country chart, a juke box list introduced in January 1944, ran under the heading "Folk Records." For a period in 1947, the term "Hillbilly" replaced "Folk." Then in 1949, the name "Country & Western" was introduced for a trio of juke box, sales and airplay charts. The latter chart originally carried this snappy title: "Country & Western Records Most Played By Folk Disc Jockeys." It wasn't until 1962 that Billboard settled on the name "Hot Country Singles."

It was no mistake that Billboard veered so heavily into music charting in the 1940s. By the early part of the decade, radio had made superstars of bandleaders like the Dorsey Brothers, Harry James and Artie Shaw. Their tours, nightclub appearances, radio dates and recording sessions were big news in Billboard and they frequently were featured on the magazine's cover, along with singing stars like Sinatra and the Andrews Sisters.

The music business was hot and Billboard had begun to dedicate more and more of its pages to music, radio and juke box coverage. Then in December 1941 came the shock of war. Quickly, the annual year-end issue was given a new theme: "Let's Go America!" and was adorned with a spirited imp sporting a rifle, with bayonet fixed. Inside, an editorial reminded entertainers of their important role in the war effort. "Performers will open the floodgates of emotions that will cause men, women and children to entrust their savings to their government. They will work themselves to a frazzle not only in creating moods favorable to the buying of bonds but will also entertain the men in uniform without thought of recompense."

Throughout the war, Billboard carried page after page of ads promoting the sale of war bonds and editorials touting show business support for the troops.

After the war, Billboard was soon on the rise again, publishing issues of 150 pages and more. The cover price was now 25 cents and an annual subscription ran $10. At the top of the masthead were Roger S. Littleford Jr. and William D. Littleford, publishers. The two brothers, grandsons of founder Bill Donaldson, had joined the company in 1933 and '34, respectively, as apprentices in the composing room.

Toward the end of the decade, a new war erupted: The War of the Speeds. In June 1948, Columbia fired the first salvo when it launched the vinyl 12-inch 33-1/3 rpm in a world long dominated by the 78 rpm record. Six months later, RCA Victor (formed by the 1929 merger of radio giant RCA and recording pioneer Victor) got off its shot: the 7-inch 45 rpm single. RCA Victor also introduced a little record player designed for the 45. Priced at only $12.95, its target audience was young and growing.

With the arrival of the 45 and the LP (as well as magnetic tape to simplify the recording process), the music industry was poised for a boom. Many new labels sprang forth in the post-war years, including Atlantic, Imperial, Mercury, Chess, Savoy, Elektra, Vanguard, Blue Note and Prestige. The modern music business had arrived—and brought with it the future of Billboard.

By 1951, the front of the magazine was dominated by reporting on music and radio. As many as 15 pages per issue were dedicated to music popularity charts. The music labels were taking page after page of ads to promote their hottest acts and new releases. Film and theater coverage had largely been swept aside. Coverage of carnivals, fairs and outdoor amusements was still much in evidence, although relegated to the latter half of the magazine.

A new generation of recording artists also had come to prominence. A front-page story in the Sept. 29, 1951, issue reported on a wave of signings of such new talent as Tony Bennett, Rosemary Clooney and Eddie Fisher.

But the real revolution was yet to come.