The Elvis Era was a period of major changes in the music industry.  Of course, there is the obvious shift in the public taste in music with the advent of rock and roll and its appeal to a younger audience.  In addition, the industry became much more competitive.  In 1956, there were 122 songs that were ranked for at least one week in the Billboard top twenty.  By 1963 that number nearly doubled to 194.  Record labels became much more willing to take a gamble with an unknown artist if the record sounded like a hit.  In 1956, 86 different artists put a record in the top twenty.  In 1963, 132 artists achieved a top twenty ranking.  The popular music pie was being cut into many more pieces.  With fewer songs sharing the spotlight in the early years, hits had more longevity.  Of the eighteen songs that reached the top spot in 1956, the average stay in the top spot was 5.7 weeks.  Two records, the double-sided hit "Don't Be Cruel" and "Hound Dog" by Elvis Presley (11 weeks), and "Singing the Blues" by Guy Mitchell (10 weeks), had the longest tenure at #1 for the entire era.  By 1963, the average stay was 2.6 weeks, the longest being "Sugar Shack" by Jimmy Gilmore & The Fireballs (5 weeks).  The success rate for independent labels increased dramatically.  In 1956 only 29 labels had a record in the Billboard top twenty.  By 1963 that number had more than doubled.  In 1956, the six major labels had 56% of the top twenty songs.  By 1963 that number was cut in half to 28%.  The likelihood of a small label getting a song in the top twenty was much greater by 1963.  In 1956, there were 15 labels that had only one top twenty record.  In 1963, there were 32.   

Elvis Presley's "Hound Dog" was the B-side to "Don't Be Cruel" "Don't Be Cruel" achieved a number one ranking on all six of Billboard's charts. "Hound Dog" was in the top spot on the "Juke Box,""Best Seller," "Jockey," "Country," and "R&B" lists -- it was #2 on the "Top 100" list.