A Definition of Progressive Rock


Criteria for defining progressive rock's musical style based on the books
  THE PROGRESSIVE ROCK FILES and ROCKING THE CLASSICS:

  1. Combines classical music's sense of space and monumental scope with rock's raw power and energy.

  2. Frequent inclusion of musical styles from other than a rock format (e.g. - classical, R&B, jazz, folk, avant-garde and world music).

  3. Complex, dynamic and multi-dimensional usually featuring intricate keyboard and guitar playing (often using a Mellotron or string synth to simulate an orchestra backing).

  4. A blending of acoustic, electric and electronic instruments where each plays a vital role in translating the emotion of compositions which typically contain more than one mood.

  5. A mixture of loud passages, soft passages, and musical crescendos to add to the dynamics of the arrangements.  Extended instrumental solos, perhaps involving some improvisation.

  6. Multi-movement compositions that center on a core musical theme. Tracks predominantly on the longish side, but structured.

  7. Subject matter typically drawn from science fiction, mythology, fantasy and utopian literature.

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