Prima's career began in the early 1930's, playing jazz trumpet in the style of fellow New Orleans trumpeter Louis Armstrong. He led his own swing band throughout most of the 30's and 40's, but during the late 40's and early 50's, he played a style of music closely resembling what we call rock and roll today.
Louis Prima was not an imitator of early R&B. On the contrary, many early R&B artists copied Prima. He was one of the only white artists who consistently showed up on the R&B charts in the mid- and late-40's, and many of his songs were covered by black artists. Prima made the charts himself with "White Cliffs Of Dover," "Robin Hood," and "I'll Walk Alone," in 1944 and '45.
Prima also brought life to Las Vegas when he put his act in the casino lounges. Many say this was the highlight of his career, as he was teamed up with first wife Keely Smith, and Sam Butera and the Witnesses. They would improvise the show, jumping from one song to the other, often in mid-tune. Many fans of Prima (like Frank Sinatra and other Vegas performers) would go directly from their show to the lounge just to see them perform. Their lax and comical attitude of classic love songs along with the combination of Prima's high-energy antics with Smith's poker-faced crooning made their popularity soar.