I've found that Experimental is pretty hard, it takes a while to be able to make something good out of strange effects. Also writing the lyrics is pretty hard.

Also Rap Metal, not so much making the music but forming bands. Most Rappers don't like Metal and most Metal guitarists, drummers, bassists don't like Rap.

I don't know if experimental (what is that, exactly?) and rap metal/rock are among the hardest musical styles to make, but they certainly are among the hardest to listen to.

Ever heard of Pink Floyd or Rage Against The Machine?

Who?

Never heard that one before

I'll just be different.

Qawwali
Konnakkol
Klezmer

the kind that is least intuitive to the musician

anytime i read anything about the 'complexity' of creating music i always remember an old jimmy page interview i read years ago. as the discussion wore on the interviewer asked page about his method for writing 'complex' riffs and arrangements for zep's tunes (this was in the mid 90s when more than 4 power chords per song could have been classified as prog).

either way page laughed his ass off and explained that regardless of how complicated it was for other people to play his parts, he never went out of his way to make something complicated. he just played the music he heard in his head in a way that was comfortable for him. he had an affinity for playing in that style so he went with it, otherwise he wouldn't have bothered playing the way he did.

jonas hellborg reiterates the same idea in a recent bass player interview while discussing crazy tempos and rhythms with his amalgamation of styles. it's not a matter of thinking about the complexity of the numbers while playing the music but just playing the music at that point the pace and punctuation become a natural reaction to the force of the music rather than a predetermined array of notes.

So in other words, I need to put my slide rule away when I compose...dammit I thought I was on to something