Source: Forced Exposure.
Let me say, right up front, I am a free jazz guy. I came to jazz via rock music, and most of my favorite jazz is loud and raw and screwy. That said, I have lately been involved in a collaborative writing project about free jazz that has forced me into parsing some of the differences between “true” free jazz, and a similar hybrid known as “spiritual jazz.”
Like all such genre distinctions, this one is arbitrary, subjective and almost imaginary.