Rock music cannot easily be defined as we have seen this type of music reinvent itself time and time again.  What has been agreed on is that rock music has been around since its emergence in the late 1940s and the term rock music describes music that has a hard edge and is performed with electric guitars, bass, drums and accompanied by a vocalist.  It is also necessary to consider the many influences that has created and shaped what rock music is.  These influences have come from people, significant bands or groups and also other types of music such as jazz, blues, classical, blue grass and country.

The emergence of rock music can be traced to the early 1940s where there was the combination of the increased popularity of the electric guitar and prominent musicians such as Chuck Berry who were in a position to push the boundaries.  The conservative nature of that time was gradually being pushed aside and emerging individuals and rock acts such as the Rolling Stones began to develop the style of rock music.

The early 1970s saw rock music become the most dominant form of popular music and also saw the emergence of many new bands that both developed the rock music sound as well as moved this music into new and uncharted territory.  Heavy metal was one of these areas that rock music had developed into thanks mainly to bands such as Led Zeppelin.  At the same time as the birth of heavy metal, the more complex sounds of psychedelic rock was also flourishing on the back of bands such as Pink Floyd.

By the end of the 1970s bands such as the Sex Pistols and the Clash changed the direction of rock music back to the sound of loud guitars, heavy beat and an attitude to match.  This was popular for a while but began to grow stale in the 1980s.  At this time college rock and alternative rock were to move into dominance on the back of bands such as R.E.M which were played throughout college radio stations.  Other bands and artists that were played were called indie rock due to the increasing popularity of small independently owned labels.

The early 1990s saw the rise of alternative rock take a dominant position in the mainstream music stakes.  This was achieved on the back of the popularity of Nirvana and alternative bands such as Sound garden.  Throughout the 1990s to now rock music has continued to grow and change as it is influenced by bands such as Limp Bizkit, Red Hot Chilli Peppers, Foo Fighters and Linkin Park.