In the first half of the 20th century, African Americans poured out of the rural South and flooded the country's urban centres in search of economic opportunity. They brought their music with them, imbuing their dance-friendly jazz and wailing blues with the latest technology. By the ‘50s, Black artists in Chicago, New York and Los Angeles would conform the spirited sounds of Memphis and New Orleans to compact, Top-40 songwriting, with the first R&B stars—Fats Domino, Ray Charles, Sam Cooke—laying the foundation for what would soon become rock 'n' roll.