I recently want to play fusion and need some guidelines on the rules of music theory for fusion. Are there some scales, modes and chords that are mandatoricly (is this a word?) played. How about rythm: measures, moderation, beats ? What's so different about jazz, or is it almost the same and should I read up on threads around here on jazz ? . I used to play metal where I was a geek for theory. I played mainly in dorian and phrygian scales, 9th, diminished and power chords. Does anyone have some tips or excercices ?