For me, the best music happens when you are not thinking and - instead - allow yourself to be a conduit for the music, without forcing your own thought processes, feelings or emotions onto the music. You simply allow it to happen.

That is why the best music often comes when you're not really thinking and that can happen when you're tired / in that inbetween spot between awake and asleep or - as with many musicians - when you use drugs.

I've done both - and while they can work, it's an exhausting way to work and they are both detrimental to your health if you try to keep it up long term. The problem with a lot of writers is that - once they hit success with one process for writing - they tend to stick with it, in the belief that that is the only way to achieve successful writing. It's not. It's just one way, that will - in the long term - fuck you up and become detrimental to your writing.

Meditation is a much healthier way to get you into the zone where you can work freely.