Rock is a popular form of music from the mid 20th century which typically features a vocal melody that is supported by accompaniment of electric guitars, a bass guitar, and drums, often with a strong back beat. Keyboard instruments such as organ, piano, or synthesizers are often used in many types of rock music. While brass and woodwind instruments, such as saxophone were common in some styles in earlier development of rock, they are less common in the newer subgenres of rock music since the 1990s.

Rock 'n' Roll started off in the early-to-mid 1950s in the United States of America. African-American artists such as Chuck Berry, Little Richard, Bo Diddley and Fats Domino played predominantly to African American crowds. While these key early rockers were indisposed to racism, local authorities and dance halls were very much divided upon racial lines. Elvis Presley and Bill Haley and the Comets, Buddy Holly, Ritchie Valens, The Big Bopper, Jerry Lee Lewis and Johnny Cash often toured and played together in dance halls and clubs across the US and Britain.

A major formative influence on rock was rock and roll, and rockabilly. In the 1960s, as British rock developed, the term rock music became popular. With the British Invasion this rerevitalized musical style spread back to the United States, and became an international cultural phenomenon with considerable social impact. Rock has evolved into a multitude of highly varying styles with widespread popularity.

Rock and Roll came from a fusion of musical cultures, and in turn its influence fed back to these cultures, a process of borrowings, influences that continues to develop rock music. Rock n Roll had runaway success in the U.S. and brought rhythm and blues influenced music to an international audience. Its success led to a dilution of the meaning of the term rock and roll, as promoters and record companies were quick to attach the label to other commercial pop.

The biggest factor that has contributed to the resurgence of rock music is the rise of paid digital downloads in the 2000s. During the 90s, the importance of the buyable music single faded when Billboard allowed singles without buyable, album-separate versions to enter its Hot 100 chart (charting only with radio airplay).

It is interesting to note that nearly all of the best selling albums of all time are still rock. In many other nations, such as the UK and Australia, rock figures much more prominently in album sales than in the US. Rap and hip hop, although popular in those nations, are not as dominant as in the USA. American bands like The White Stripes and The Killers have more success in the UK than in the USA, and British bands such as The Libertines, Franz Ferdinand, Coldplay, Oasis, and Arctic Monkeys are still the UK's biggest selling artists. Nowadays, Emo, a marginal genre, is arguably growing in popularity in the UK. Nothing gives a high to the music lovers than to head-thump on the beat of rock and literally get rocked.