"'Soul Man' came about during one of the riots. I was watching TV and they said something about businesses being bypassed when 'soul' was written on the door. That reminded me of Passover in the Bible. So I thought about this 'soul' thing: there's a lot of pride in it. I didn't look at the rioting as destroying. I looked at it as frustrated people taking out their frustrations on whatever got in their way. I told David about it and we started working on it. Everything just clicked."

Hayes recalls the Stax studio. "We only had a one-track recorder at first. [Label-owner] Jim Stewart was considered the king of one-track. If anybody screwed up, we had to start all over again and [trumpet player] Wayne Jackson's lips would fall off. Eventually we got two-track when Tom Dowd came in and installed it for us.

"Regarding arrangements, we did them in out heads, where Motown may have had them written out. We went on feel. I continue to do that. Otis [Redding] would come in sometimes with just an idea. He would get behind the microphone and say 'work up a groove' and start doing lyrics spontaneously - [singing] 'I can't turn you loose.'"

Though deeply in the groove, Hayes was always a thinking man with a conscience as well. "I was active even in high school in marches and things. I was afraid but I thought it was the right thing to do. When Dr. King was killed [in '68] I went through a period when I couldn't write, couldn't create. I just went blank. I was so hurt by that and I had so much bitterness and hatred for racist attitudes. Then one day after about a year I cognized: 'Hey man, the only way you can make a change is to do what you do.' So I got busy again."

Hayes had recorded a very casual album in '67 that received a fair amount of critical praise and was given the opportunity to record again in '69. This time he took the affair more seriously, but still felt no particular pressure to succeed as an artist. That album became Hot Buttered Soul, and it established the recording career of Isaac Hayes.

Hayes was shocked by his solo success. "I couldn't believe it because I had been behind the scenes so long. When David and wrote together, we wrote for other people so we had to match their personalities. I had a background in blues, jazz, pop, even classical and I wanted to get it all out. I had a funky groove underneath, but those strings on top. I was happy with it for myself, but a few million other people got into it too," he laughs.