Rock'n'roll
Rock and roll (often shortened to Rock'n'roll) is a style of popular music that appeared in 1950 in the USA and was the earliest stage in the process of development of rock music. Rock and roll also means the dance which is perfomed to this music, so the both meanings are sometimes confused. Another difficulty in terminology is that in western countries the term "rock and roll" is often used to denote rock music in general, and thus any rock style like grunge or rockabilly or ska etc. may be called rock and roll. Rock and roll in its narrower meaning has such characteristic features as fast tempo (4/4), wide usage of slang in lyrics, a lot of freedom of actions during performance on stage. Traditional musical instruments for rock'n'roll (as well as for tens of other styles today) are electric guitar, bass guitar, drums and piano. The term "rock and roll" in its modern meaning is considered to be introduced by Alan Freed, a DJ from Cleveland.
Rock and roll became the first music style in the USA to be equally played by people of both races, which partially contributed to the lowering of racial confrontation of that period (the style itself being completely apolitical). Besides the songs written in the new style, early rock and roll authors also played and sang blues, country, jazz, traditional songs while introducing elements of rock and roll into them. Elvis Presley is considered to be the most famous personality in the history of rock and roll, although there were many other talented performers that made their contribution into the development of rock and roll.