<P> By the early 1940s, the term "rock and roll" was also being used in record reviews by Billboard journalist and columnist Maurie Orodenker . In the May 30, 1942, issue, for instance, he described Sister Rosetta Tharpe's vocals, on a re-recording of "Rock Me" with Lucky Millinder's band, as "rock - and - roll spiritual singing", and on October 3, 1942, he described Count Basie's "It's Sand, Man!" as "an instrumental screamer...(which)... displays its rock and roll capacities when tackling the righteous rhythms ." In the April 25, 1945 edition, Orodenker described Erskine Hawkins' version of "Caldonia" as "right rhythmic rock and roll music", a phrase precisely repeated in his 1946 review of "Sugar Lump" by Joe Liggins . </P> <P> A double, ironic, meaning came to popular awareness in 1947 in blues artist Roy Brown's song "Good Rocking Tonight", covered in 1948 by Wynonie Harris in a wilder version, in which "rocking" was ostensibly about dancing but was in fact a thinly - veiled allusion to sex . Such double - entendres were well established in blues music but were new to the radio airwaves . After the success of "Good Rocking Tonight" many other R&B artists used similar titles through the late 1940s . At least two different songs with the title "Rock and Roll" were recorded in the late 1940s: by Paul Bascomb in 1947, and Wild Bill Moore in 1948 . In May 1948, Savoy Records advertised "Robbie - Dobey Boogie" by Brownie McGhee with the tagline "It jumps, it's made, it rocks, it rolls ." Another record where the phrase was repeated throughout the song was "Rock and Roll Blues", recorded in 1949 by Erline "Rock and Roll" Harris . </P> <P> These songs were generally classed as "race music" or, from the late 1940s, "rhythm and blues", and were barely known by mainstream white audiences . However, in 1951, Cleveland, Ohio disc jockey Alan Freed began broadcasting rhythm, blues, and country music for a multi-racial audience . Freed, familiar with the music of earlier decades, used the phrase rock and roll to describe the music he aired over station WJW (850 AM); its use is also credited to Freed's sponsor, record store owner Leo Mintz, who encouraged Freed to play the music on the radio . Originally Freed used the name "Moondog" for himself and any concerts or promotions he put on, because he used as his regular theme music a piece called "Moondog Symphony" by the street musician Louis "Moondog" Hardin . Hardin subsequently sued Freed on grounds that he was stealing his name and, since Freed was no longer allowed to use the term Moondog, he needed a new catchphrase . After a night of heavy drinking he and his friends came up with the name The Rock and Roll Party since he was already using the phrase Rock and Roll Session to describe the music he was playing . As his show became extremely popular, the term caught on and became widely used to describe the style of music . </P> <P> Rock and roll music emerged from the wide variety of musical genres that existed in the United States in the first half of the twentieth century, among different ethnic and social groups . Each genre developed over time through changing fashion and innovation, and each one exchanged ideas and stylistic elements with all the others . The greatest contribution came from the musical traditions of America's black population, with an ancient heritage of oral storytelling through music of African origin, usually with strong rhythmic elements, with frequent use of "blue notes" and often using a "call and response" vocal pattern . African music was modified through the experience of slavery, and through contact with white musical styles such as the folk ballad, and instruments, such as the Spanish guitar . New styles of music emerged among black Americans in the early twentieth century, in the form of blues, ragtime, jazz, and gospel music . According to the writer Robert Palmer: </P>

Who sang the first rock n roll song