In 1970, Gil Scott-Heron was a young man, expressing his frustration in the most honest means he knew-- his poetry. He performed it live, backed on this particular record mostly by two percussionists (with three tracks featuring his piano playing a couple of those with another vocalist). The words are of the period, and of the age he was, and they range from brilliant ("The Revolution Will Not Be Televised") to amusing ("Whitey on the Moon") to somewhat embarassing ("The Subject Was F*****s") social commentary. I suspect Scott-Heron would be somewhat embarassed by at least some of this material, but it is largely brilliant.
Musically it is straightforward, with simple hand percussion rhythms set up behind him, Scott-Heron let's forth his words in a suitably dramatic fashion. Honestly, I think his words speak best for him, so I'll quote a few pieces:
"Martin is dead. With Martin as our leader, we prayed and marched and marched and prayed. Things were changing, things were getting better, but things were not together.
"With Malcolm as our leader, we learned and thought and thought we had learned. Things were changing, things were getting better, but things were not together.
"And now it is your turn: we are tired of praying and marchign and thinking and learning. Brothers want to start cutting and shooting and stealing and burning. You are 300 years ahead in equality, but next summer may be too late".
The above quote is from "Evolution (and Flashback)". If it appeals to you, check this record out, the truly great material on the album is like this.