"One of the slickest talents to come up in the country field in a long, long time," said a Jan. 29, 1955, Billboard review of the new Elvis Presley release "Milk Cow Blues." Fourteen months later, Presley achieved his first No. 1 Billboard pop hit with "Heartbreak Hotel." The rock era was upon us and so was a new era in Billboard's history. In November 1955, Billboard rolled out its first 100-position pop chart, the Top 100. Then in the issue of Aug. 4, 1958, the Hot 100 chart was introduced, combining sales and airplay for the first time. The first No. 1: "Poor Little Fool" by Ricky Nelson.

When the 1960s rolled around, the magazine was still called The Billboard and coverage of tent shows and carny pitchmen still shared space with music stories, charts and reviews. It was time for a radical change. And so, with the issue dated Jan. 9, 1961, the carnival and fair coverage was spun into a new publication, Amusement Business, and The Billboard took on a new name: Billboard Music Week. "For the first time, Billboard is no longer a general show business publication, but a weekly business journal for the professional user of music, with the emphasis on recordings, and of music playback equipment," the magazine declared.

Two years later, it was back to the drawing board for another facelift and another new name. At last, the magazine was simply, "Billboard." ("We bow to the will of our readers," the magazine explained.) Remarkably, the cover price was still only 50 cents; an annual subscription a mere $15. The magazine was now printed on glossy paper with more photos and touches of color everywhere, especially on the charts and reviews pages.

As the '60s unfolded, the appetite for music was growing and Billboard's music coverage expanding. Albums, which in the pop world had previously been secondary to singles, were gaining in significance. Prior to 1960, Billboard ran album charts of various lengths, but none ever reached more than 50 positions. That changed in 1961. To reflect the growth in album sales and the market shift from the old monaural (or "mono") albums to stereo, Billboard began publishing a 150-position monaural chart and a 50-position stereo chart.

By 1963, the album charts were combined into a single 150-position list. In April 1967, that was expanded to 175 slots. The following month, Top LP's reached its current length of 200 titles. The first No. 1 on the 200-position chart: Andy Williams' "Days of Wine and Roses."

The next revolution at Billboard occurred in the issue of Feb. 1, 1964. In the weeks leading up to that momentous issue, singles by the Angels, Jimmy Gilmer & the Fireballs, Nino Tempo & April Stevens, Dale & Grace, the Singing Nun and Bobby Vinton (twice) had reached No. 1 on the Hot 100. Then, in that Feb. 1 issue, a quartet from Liverpool, England, called the Beatles hit the top of the chart with "I Want To Hold Your Hand."

The Beatles's success in 1964 remains unsurpassed. According to Billboard chart expert Fred Bronson, the group had 30 entries on the Hot 100 that year (an all-time record that stands today) including six that went to No. 1. What's more, they opened the door to a host of other British acts in an invasion of talent that would enliven the music business and Billboard's pages for the next decade.

With Billboard firmly established as "The Bible of the Music Industry," it was time for a music man to take his place at the top of the staff. That man would be Paul Ackerman, who was named editor of Billboard in 1965. Ackerman was the magazine's longtime music editor, overseeing its coverage during the birth of rock'n'roll. A popular and influential figure, Ackerman served as editor and later executive editor until his retirement in 1973. He died four years later. In 1995, he became Billboard's first member of the Rock and Roll Hall of Fame. (Seymour Stein, who started his career in the charts department at Billboard and later founded Sire Records, was inducted in the class of 2005.)

By 1970, Billboard was reporting on the dawn of the "cassette market." Already 8-track tapes, introduced in 1965, had taken their place in Billboard's coverage, with a page titled Tape CARtridge. If the magazine was a bit thin at the start of the decade, within 10 years it was bursting at the seams.

This was the disco era, the age of the Bee Gees and "Saturday Night Fever." Album sales were reaching new heights and the pages of Billboard were the best place for labels and artists to trumpet their successes.

Of course, what goes up, must come down. The industry sunk into the doldrums in the early 1980s. The dance was over -– until a shiny little 5-inch disk came along and brightened industry prospects. The compact disk, introduced into the U.S. market in 1983, performed an amazing trick. Not only did music lovers flock to stores to buy the latest titles on CD from pop superstars like Michael Jackson, Whitney Houston and Madonna, they also went out and re-purchased all of the old favorites that they previously had collected on now-scratchy vinyl.

The CD era started quietly. In 1982, U.S. business was off by 9% from the previous year. The industry had little to cheer about. The April 2, 1983, issue of Billboard carried a front-page story headlined: "Labels Closing Out Era Of The 8-Track." Just one month later, Billboard reported that retailers were expressing "the highest hopes for the small, virtually indestructible" compact disk.

Their hopes were not misplaced. The CD brought a windfall like no other for the music business and it carried Billboard along on a wave of unparalleled prosperity.