Often while chatting with friends and students, questions about “what is exactly” or “what are fundamental characteristics” of Progressive Rock compositions comes up.
What I noticed is that many people think that the fundamental characteristics are just presence of Spare Time Signatures (or Odd Time Signatures) and a keyboard player who can play solos… Honestly I find this a wrong definition and also very reductive, so here is some (and I repeat SOME) of the “must have” in order to define a track Progressive Rock or Progressive Metal. With that said remember that music is ART, so it is CREATIVITY mostly and therefore rules are made to be followed and to be broken (when you’ve learned them really well and you became capable of mastering them!).
Sonic V 