10 bloody years +.
It totally depends, but ‘good stuff’ takes me ages. I need a lot of time for reflection, and resting my ears and mind from any given project. I’m very picky about vocals too, so a lot of projects get slowed up because of that. I often revisit things and update the mix because my ears and skills have evolved. Or I’ve got better hardware to do better things. It sure is a lot of mental intensity to really get a song in context of a larger project done, and then another whole thing to put that out there in an honorable way. It’s important to get it right, if anything for me, because that’s how I evolve.
For the heart to express the essence of a song? A day or two if it is quick. Making it into a masterpiece? A difficult and slow process.