R&B/Soul

R&B and soul are two closely linked genres, close enough that AllMusic and Wikipedia both treat one as growing directly out of the other. R&B evolved out of jump blues in the late 1940s within African American communities in the Deep South, keeping the tempo and drive of jump blues while trimming the instrumentation down and putting the focus on the song rather than instrumental improvisation (AllMusic, n.d.-k; Rhythm and blues, n.d.). In practice, it was blues chord changes played over an insistent backbeat, carried through the 1950s by vocalists like Ray Charles and vocal groups like the Drifters (AllMusic, n.d.-k). Picture R&B as the direct ancestor in a family tree. It laid the groundwork rock and roll would later build on, and it is also the root soul eventually grew from.

Soul itself formed when R&B moved into cities and picked up more commercial polish during the 1960s (AllMusic, n.d.-l). It kept R&B's backbone but loosened it, adding a funkier, looser feel, and it leaned heavily on the vocal styles and call-and-response structure of gospel music from the Black church (AllMusic, n.d.-l; Soul music, n.d.). Sam Cooke is a good example of that link. He brought the smooth, melismatic vocal style he had developed in the gospel group the Soul Stirrers straight into secular music.

Soul was never one uniform sound. Different American cities shaped it differently. In New York, Philadelphia, and Chicago, the focus stayed on vocal interplay and smooth studio production. In Detroit, Motown built a pop-leaning sound that blended gospel, R&B, and rock and roll. In the South, the sound got tougher, leaning on syncopated rhythms, raw vocals, and blaring horns (AllMusic, n.d.-l). It is a bit like regional cooking styles built from the same core ingredients. Every city started with the same basic recipe, but the final dish tasted different depending on where it was made.

By the late 1960s and into the 1970s, soul began splitting into new directions entirely. James Brown and Sly Stone pushed it toward funk, while Kenny Gamble and Leon Huff shaped the smoother Philly soul sound (AllMusic, n.d.-l). Soul never disappeared after that split. It kept shaping R&B through the decades that followed, and pockets of traditional soul performers have kept the original sound alive ever since (AllMusic, n.d.-l).

Sources:

AllMusic. (n.d.-k). R&B music genre overview. https://www.allmusic.com/genre/r-b-ma0000002809
AllMusic. (n.d.-l). Soul music genre overview. https://www.allmusic.com/genre/soul-ma0000002865
Rhythm and blues. (n.d.). In Wikipedia. https://en.wikipedia.org/wiki/Rhythm_and_blues
Soul music. (n.d.). In Wikipedia. https://en.wikipedia.org/wiki/Portal:R&B_and_Soul_Music