Progressive rock appeared in the late 1960s when rock artists wanted to break down the barriers of radio formatted pop and rock and progress this music genre to a place where it could achieve a more sophisticated sound, similar to that of classical music or jazz. Progressive rock is very hard to define in one conclusive way and we have progressive rock bands to prove that. Some of the most important bands of the 70s that defined this rock form did not have the same sound.

Psychedelic music is believed to be the starting point of progressive rock. Some people also believe that bands like The Beatles contributed to the progressive rock movement. However, the two progressive rock bands that most people see as being the first of this new- found genre were King Crimson and Yes. These progressive rock bands appeared at the end of the 1960s and although the first band was attributed to hard progressive rock sub- genre and the second to symphonic rock, they were both catalogued as progressive rock bands, as their sound was unique and more sophisticated. Genesis is yet another rock band that aspired to progressive rock. Their third progressive rock album set things straight for this band. They were a symphonic rock band and thus a progressive rock band.

Great Britain was the first country that started the progressive rock movement, but Italy was not far behind either. Banco Del Mutuo Soccorco and Premiata Forneria Marconi were progressive rock bands that led the way for all rock bands all over Europe to progress and define this rock genre. As far as the progressive rock movement is concerned, these two European countries were the ones that opened all doors and invited all rock bands to evolve and give the world great progressive rock albums. However, Great Britain is still the top promoter of progressive rock bands, with Caravan, another progressive rock band from this country, being the one that defined the third sub- genre of progressive rock: Canterbury. So, at the end of the 1960s, progressive rock bands established three sub- genres: hard prog, symphonic and Canterbury.

The 1970s represented the crowning of progressive rock as a genre and some of the greatest progressive rock albums were released in this decade. Jethro Tull's ?Thick as a brick? or Rush's ?2112? are only two of the most appreciated progressive rock albums released in the 70s. Moreover, this decade brought another ten sub- genres of progressive rock to life, and many progressive rock bands came forth in this period. As if progressive rock was not complicated enough, art folk, classical prog, folk prog, ambient, Rio, pomp prog, jazz fusion, electronic, Zeuhl and krautrock were listed as sub- genres of the 60s rock genre.

In the next two decades, progressive rock did not progress as much as it had up to that moment. In the 80s, it was dethroned by the punk movement and progressive rock bands chose to give birth to another sub- genre: neo progressive. There were few progressive rock albums released in the 80s, some of the most prolific ones being Rush's ?Moving Pictures? or Fate's Warning's ?No Exit?. Progressive metal rock was also listed as a sub- genre in this period. The 1990s were dominated by the development of metal prog, through Dream Theatre. This decade is mainly characterized by the revival of the progressive scene of the seventies.