R&B, an abbreviation for "rhythm and blues", is a style that arose in the 1930s and 1940s. Early R&B consisted of large rhythm units "smashing away behind screaming blues singers (who) had to shout to be heard above the clanging and strumming of the various electrified instruments and the churning rhythm sections". R&B was not extensively recorded and promoted because record companies felt that it was not suited for most audiences, especially middle-class whites, because of the suggestive lyrics and driving rhythms. Bandleaders like Louis Jordan innovated the sound of early R&B, using a band with a small horn section and prominent rhythm instrumentation. By the end of the 1940s, he had had several hits, and helped pave the way for contemporaries like Wynonie Harris and John Lee Hooker. Many of the most popular R&B songs were not performed in the rollicking style of Jordan and his contemporaries; instead they were performed by white musicians like Pat Boone in a more palatable mainstream style, which turned into pop hits. By the end of the 1950s, however, there was a wave of popular black blues rock and country-influenced R&B performers like Chuck Berry gaining unprecedented fame among white listeners.