In the 1950s and 60s, the blues transformed:

• Rhythm and blues added electric instruments and a stronger backbeat, becoming the direct precursor to rock and roll
• Soul music merged blues with gospel's passionate vocal delivery, producing secular songs with religious power
• Ray Charles broke the barrier first, singing gospel melodies with secular lyrics — scandalizing the church but electrifying audiences
• Sam Cooke brought gospel's smooth technique to pop, Otis Redding brought raw power, and Aretha Franklin brought it all
• Motown in Detroit polished soul into pop perfection