Legacy Recordings

In a broad sense, pop is any music based on memorable melodies, repeated sections (usually, but not always, verses and choruses), and a tight, concise structure that keeps the listener's focus on those elements. Pop music has been a profitable industry in America since the 19th century, but for these purposes, pop is a style that took shape in the post-rock & roll era, once the more conservative elements of the record industry had come to terms with the new musical landscape. Pop emerged in the late '50s, as the initial rock & roll craze began to die down, and a lighter, smoother (but still similar) alternative to rock was needed. Mostly a singles medium, pop was influenced by the beat, arrangements, and style of rock & roll (and sometimes doo wop), and it didn't sound bad on the radio next to rock & roll. But pop didn't rock as much as rock & roll. It was about professional craft, both in the songwriting and the studio production, and had little to do with the edge or attitude of rock. As the '60s wore on, pop began to incorporate touches of psychedelia and blue-eyed soul; by the '70s, pop had mellowed substantially, thanks in part to the singer/songwriter movement and Bacharach's brand of smooth adult pop. Some of pop's biggest acts in the '60s included the Beach Boys, the Four Seasons, the Everly Brothers (entering a different phase of their career), the Association, the Rascals, the Righteous Brothers, and (in the U.K.) the Walker Brothers and Petula Clark; other major figures included composer Burt Bacharach, producer Phil Spector, and Brill Building songwriting teams like Barry/Greenwich and Goffin/King. The classic '60s-style strain of pop morphed into AM pop and soft rock by the mid-'70s, but today it dominates good-time oldies radio formats. --All Music Guide

Rock & Roll is often used as a generic term, but its sound is rarely predictable. From the outset, when the early rockers merged country and blues, rock has been defined by its energy, rebellion and catchy hooks, but as the genre aged, it began to shed those very characteristics, placing equal emphasis on craftmanship and pushing the boundaries of the music. As a result, everything from Chuck Berry's pounding, three-chord rockers and the sweet harmonies of the Beatles to the soulful pleas of Otis Redding and the jarring, atonal white noise of Sonic Youth has been categorized as "rock." That's accurate -- rock & roll had a specific sound and image for only a handful of years. For most of its life, rock has been fragmented, spinning off new styles and variations every few years, from Brill Building Pop and heavy metal to dance-pop and grunge. And that's only natural for a genre that began its life as a fusion of styles.

In the terminology of rap music, Hip-Hop usually refers to the culture -- graffiti-spraying, breakdancing, and turntablism in addition to rapping itself -- surrounding the music. As a style however, hip-hop refers to music created with those values in mind. Once rap had been around long enough to actually have a history, hip-hop groups began looking back to old-school figures including MCs like Kurtis Blow and Whodini, and DJs like Grandmaster Flash and Afrika Bambaataa. In fact, the latter's Zulu Nation collective sprang up in the late '80s around two of the most notable hip-hop artists, De La Soul and A Tribe Called Quest. With rap music's mainstream breakout during the '90s, dozens of hip-hop artists pointed the way back to the old school, including underground rappers like Mos Def and Pharoahe Monch. --All Music Guide

Evolving out of jump blues in the late '40s, R&B laid the groundwork for rock & roll. R&B kept the tempo and the drive of jump blues, but its instrumentation was sparer and the emphasis was on the song, not improvisation. It was blues chord changes played with an insistent backbeat. During the '50s, R&B was dominated by vocalists like Ray Charles and Ruth Brown, as well as vocal groups like the Drifters and the Coasters. Eventually, R&B metamorphosed into soul, which was funkier and looser than the pile-driving rhythms of R&B. Soul came to describe a number of R&B-based music styles.

Country music is about tradition, yet its simple form lends itself to endless variations on similar themes. Like blues -- the two genres often shared themes, melodies and songs -- country is a simple music at its core. Most of its songs are built around three chords and a plain melody, but these forms are so basic, they allow for many different styles, from the gritty sounds of honky tonk to the jazzy improvisations of Western Swing. Country music grew out of American Southern folk music, both Appalachian and blues, and old-time country was simple and folky, with just guitars and fiddles.