The blues are at the heart of rock and roll. Their musical structure, as well as their emotions and intensity, gave shape to the sound. The blues tell the story of the African-American migration, from the Mississippi Delta to Chicago’s southside. The blues began with a voice and a guitar engaged in a dialogue about the travails of everyday life. In the 20s, the blues were sung along the black vaudeville circuit; Howlin’ Wolf and B.B. King were captured on 78 rpm records and broadcast on regional radio stations. In the 1950s, Billboard adopted the term "rhythm and blues" which brought a large multiracial audience to R&B. R&B foreshadowed rock and roll. In 1947, Roy Brown wrote and sang "Good Rockin’ Tonight" and in 1954, up-and-coming Elvis Presley released his own country-inflected version.

Like the blues, folk music was about a voice and a guitar. Blues songs limned the early African-American experience in expressionistic, emotional terms; folk songs took on a more narrative form, tales of the underclass told in verse and set to melodies that often had English or Celtic roots. Songs survived via oral tradition, passed from generation to generation in rural settings like the deep south or Appalachia. During the Great Depression, itinerant folksinger Woody Guthrie traveled from the Dust Bowl-ravaged midwest to California, recording his observations in songs like "This Land is Your Land" that have become American standards. During the ‘30s, Manhattan-bred Pete Seeger also hit the road to seek out authentic folk sounds. In the late ‘40s, as part of the Weavers quartet, Seeger brought folk music ("If I Had A Hammer") to a mass audience. These folk artists and their music inspired Bob Dylan. When he plugged in an electric guitar and shocked the folk world, Dylan used folk’s storytelling power to alter the course of rock and roll.

Like the blues, gospel could be a plaintive cry, acknowledging the hardship of being poor and black in mid-century America. But gospel was meant to uplift its listeners and to praise the lord. The blues often dwelled on the weaknesses and pleasures of the flesh; gospel stirred and strengthened the spirit. Dinah Washington, Queen of the Blues, was a teenage gospel star in the ‘40s. Gospel’s greatest voice, Mahalia Jackson, went on to pop fame performing only sacred music. Arethra Franklin always cites Jackson as model and mentor. Sam Cooke was a member of the gospel group Soul Stirrers.

The vocal style known as Doo Wop evolved out of streetcorner serenading in cities like Philadelphia, Detroit, and New York. In the mid-’50s, rival teenage groups would compete with voices instead of fists to rule their neighborhoods. These cool combos were inspired by older African-American vocal ensembles like the Ink Spots. Doo wop, as the name suggests, was more about sounds than words themselves; hits like the Silhouettes "Get A Job" were dazzling displays of vocal pyrotechnics using near-nonsense rhymes. Many of these tunes remain the most evocative in rock and roll: "Sh-Boom" (The Chords), "In the Still of the Night" (The Five Satins), "I Only Have Eyes for You" (The Flamingos), "Book of Love" The Monotones), "Why Do Fools Fall in Love?" (Frankie Lymon and the Teenagers ). Dion and the Belmonts parlayed streetwise New York City attitude into hits like "The Wanderer" and "Runaround Sue."

The Motown Sound took off in 1960 when label founder Berry Gordy Jr. released the Miracles’ "Shop Around" and the single became a major R&B and pop hit. Within two years, Gordy was overseeing a unique hit-making factory. His Detroit-based company was an African-American-owned enterprise whose offerings appealed to a racially mixed audience when America was otherwise deeply divided by color. Gordy worked with local talent, developing such stars as The Supremes, Martha Reeves, the Temptations, Stevie Wonder, Gladys Knight, and the Jackson Five. When the British Invasion threatened to wipe the charts clean of homegrown talent, the Motown Sound held firm on the charts.

Dennis Wilson loved to surf and, in 1961, he urged his brother Brian to write about it for their family’s Four-Freshman-style vocal group, which they called the Beach Boys. Brian wasn’t a surfer, but he created Chuck Berry-style rock and roll tunes that idealized Southern California beach life. In "Surfin’," "Surfin’ U.S.A.," and "Surfin’ Safari," the Beach Boys sang of a world that was still exotic to most Americans. Furthering the Beach Boys’ fantasy of west coast sun and fun was Jan and Dean’s "Surf City." In 1963, two instrumental hits, "Pipeline" and "Wipeout" immortalized the echo-laden style that evoked the rush of riding waves. Quentin Tarantino renewed interest in the genre by using surf music to propel "Pulp Fiction."

The British Invasion bands made the familiar exotic and thrilling again. The Beatles and Rolling Stones had taken R&B and early rock and roll and transformed it in to something of their own, rudimentary but rocking. Their hair made headlines, but their sound was the news. Among the English artists whose combination of catchy singles and cute looks yielded immediate pop chart success: The Dave Clark Five, Gerry and the Pacemakers, and Herman’s Hermits. Harder-rocking, more blues-based acts followed: The Who and Yardbirds.

Punk was an attitude long before it became a label. In 1975, a fashion designer/band manager found Patti Smith, Blondie, the Ramones, and Talking Heads in New York’s Bowery. Back in London, the same designer manufactured the Sex Pistols. The class of ‘75 found fame and fortune before punk went underground where it evolved into a still-thriving hardcore movement.

In 1977, thanks to the Bee Gees’ hits and John Travolta’s dancing, Saturday Night Fever made disco a cultural force. But disco had been evolving in the dance club underground since the early ‘70s. Disco was rooted in R&B and funk; DJs at clubs catering to a mostly gay male clientele unearthed the most dance-worthy records to shape the disco experience, which became an ecstatic blend of gyrating bodies, lights, and beats-per-minute. Disco crossed over into rock with the Rolling Stones ("Miss You") and Blondie ("Heart of Glass"). Though disco’s dance crazes were ephemeral, the music never died. It evolved into a broad range of dance music and the model for the European rave culture.

The sound that would become heavy metal emerged from the British blues-based rock of the late ‘60s. Led Zeppelin was formed by Jimmy Page in 1968 after his blues-rocking Yardbirds broke up. Page emulated Howlin’ Wolf but the band utilized the cranked-up volume, fast ad flashy guitar solos, wailing vocals, aggressive rhythms, and occult subject matter than would become metal trademarks. Kiss became the ultimate heavy metal fantasy band, transforming themselves into comic-book style characters. By the late ‘70s, American heavy metal reflected the musical, sartorial, and lifestyle influence of Led Zeppelin. On the West Coast, Van Halen and Aerosmith featured flamboyant, scarf-wielding sexy frontmen and virtuoso lead guitarists, and were known for their hard-partying ways. On the east coast, Bon Jovi and Guns’N’Roses similarly hit it big. By the end of the decade, black leather-clad Metallica found fans among metalheads and grunge rockers

Funk is R&B stripped down to two essentials: a fat-bottomed groove and a ribald voice. James Brown and his Famous Flames pioneered funk in the ‘60s. Sly and the Family Stone had a similar gospel-like zeal, although more pop-oriented than Brown’s extended workouts. Doo wap singer George Clinton transformed Brown-style jams into psychedelic extravaganzas in the mid-‘70s. He inspired artists from Prince to Earth, Wind, and Fire, and Kool and the Gang.

When two Seattle bands, Pearl Jam and Nirvana, topped the charts in 1992 with major label debuts, talent scouts flocked to the Pacific Northwest. Seattle was home to a band-friendly bohemia as well as the Indie label Sub Pop, where Nirvana got its start. Because it was a scruffier variety of Indie rock, the look and sound became known as grunge. But musically local artists often had more in common with classic rock icons than college bands. Nirvana’s "Smells Like Teen Spirit" shows the influence of staple Boston. Pearl Jam made jamming rock that recalled the heavier side of Neil Young. Grunge-inspired bands popped up throughout America and England. The hype surrounding grunge abruptly ended with the suicide of Nirvana bandleader Kurt Cobain in 1994.