Rock music

Rock music is a form of popular music that began in the United States in the late 1940s and early 1950s under the name "rock and roll." It evolved into many different styles between the late 1950s and mid-1960s, mainly in the U.S. and the United Kingdom. Its earliest sound came from classic rock and roll, which itself grew out of African-American blues and rhythm and blues, as well as country music. The genre also took strong cues from electric blues and folk, and mixed in elements from jazz and other musical forms. At its core, rock is built around the electric guitar, usually played in a band that includes an electric bass guitar, drums, and one or more singers.

Most rock songs follow a 4/4 time signature and a verse–chorus structure, though the genre has become extremely varied over time. Like pop music, its lyrics often focus on romantic love, but they also tackle a wide range of topics, frequently touching on social or political issues. From the 1960s through the 2010s, rock was the most popular music genre in the United States and much of the Western world.

In the mid-1960s, rock musicians began to push the album format ahead of the single as the main way to create and consume recorded music, with the Beatles leading this shift. Their work gave the genre greater cultural legitimacy in the mainstream and kicked off a rock-driven album era in the music industry that lasted for decades. By the late 1960s, during the "classic rock" period, several distinct subgenres had emerged. These included hybrid styles like blues rock, folk rock, country rock, southern rock, raga rock, and jazz rock, which helped shape psychedelic rock, influenced by the countercultural psychedelic and hippie scene. New genres also arose, such as progressive rock, which expanded artistic boundaries; heavy metal, known for its aggressive, thick sound; and glam rock, which emphasized showmanship and visual flair. In the second half of the 1970s, punk rock emerged as a reaction, offering stripped-down, energetic critiques of society and politics. Punk then influenced new wave, post-punk, and eventually alternative rock in the 1980s.

Starting in the 1990s, alternative rock took over as the dominant force in rock music and broke into the mainstream through grunge, Britpop, and indie rock. More subgenres followed, including pop-punk, electronic rock, rap rock, and rap metal. Some movements were deliberate attempts to revisit rock’s past, like the garage rock and post-punk revivals of the 2000s. Since the 2010s, rock has lost its place as the leading popular music genre worldwide, but it remains commercially successful. The growing influence of hip-hop and electronic dance music can be heard in rock, especially in the techno-pop scene of the early 2010s and the pop-punk-hip-hop revival of the 2020s.

Rock has also been a vehicle for cultural and social movements, giving rise to major subcultures. In the U.S. during the 1950s to mid-1960s, there were greasers, while the U.K. saw teddy boys and rockers. The 1960s brought the hippie movement and the wider Western counterculture that spread from San Francisco, which continues to this day. Similarly, 1970s punk culture spawned goth, punk, and emo subcultures. Carrying on the folk tradition of the protest song, rock has been tied to political activism and shifts in social attitudes about race, sex, and drug use. It is often seen as a way for youth to rebel against adult conformity. At the same time, its high commercial success has led to accusations of selling out.

**Characteristics**

The sound of rock traditionally centers on the amplified electric guitar, which took its modern form in the 1950s alongside the rise of rock and roll. It was heavily shaped by the sounds of electric blues guitarists. The electric guitar in rock is usually supported by an electric bass guitar, which jazz pioneered in the same era, and by percussion from a drum kit that includes drums and cymbals. This trio of instruments is often joined by others, especially keyboards like the piano, the Hammond organ, and the synthesizer. The basic rock setup came from the standard electric blues band lineup: a prominent lead guitar, a second chordal instrument, bass, and drums. A group that plays rock music is called a rock band or rock group, typically with three (the power trio) to five members. A classic rock band is a quartet where members cover roles such as vocalist, lead guitarist, rhythm guitarist, bass guitarist, drummer, and often a keyboard player or other instrumentalist.

Rock music is traditionally built on simple syncopated rhythms in a 4/4 meter, with a repetitive snare drum backbeat on beats two and four. Melodies often come from older musical modes like Dorian and Mixolydian, as well as major and minor scales. Harmonies range from common triads to parallel perfect fourths and fifths, and dissonant harmonic progressions. Since the late 1950s, and especially from the mid-1960s onward, rock has often used a verse–refrain structure borrowed from blues and folk music, though there is plenty of variation. Critics have pointed out the genre’s eclecticism and stylistic diversity. Because of its complex history and tendency to borrow from other musical and cultural forms, it has been argued that "it is impossible to bind rock music to a rigidly delineated musical definition." In 1981, music journalist Robert Christgau said, "the best rock jolts folk-art virtues—directness, utility, natural audience—into the present with shots of modern technology."