This is ELP's most popular song from their most popular album. The song is most commonly interpreted as ELP's take on a shortened history of the world into a futuristic tale. The First Impression begins on the "Cold and misty morning" of the Earth's birth, through the ice age ("Where the seeds have withered, silent faces in the cold"), and to man's growing lust for money ("Now their faces captured in the lenses of the jackals for gold"), which leads to various wars. Afterwards, the world is described as a carnival, wherein various elements of humanity are reduced to circus sideshows ("A bomb inside a car," "Pull Jesus from a hat"), representing the human race's growing selfishness and indifference toward others. Even human misery is described as a "specialty" in the "show."
The second part of the First Impression focuses on the growing artificialization of the world, describing something as natural as "A real blade of grass" as some bizarre circus attraction. Despite the fact that the world is becoming more and more consumed by artificiality and given control to computers (see Third Impression), the human race insists that it is still in control, as it created all that the "Carnival" encompasses ("We would like it to be known the exhibits that were shown were exclusively our own.").
The Second Impression is an instrumental piece (mostly a piano solo), symbolizing the blissful ignorance of humanity towards the impending danger of the conquest of the computers, which culminates in the Third Impression. At this point, the "machines" have concluded their superiority to humanity and begin to take on mankind's necessity to prove their own superiority. The computers are represented by heavily distorted vocals, while the voice of the all-representative "Man" is clean and without effect. The computers finally wage a violent conquest of the Earth. Mankind is shocked that its own creation is fighting back against him ("Walls that no man thought would fall") and is unprepared for the conflict. Finally the machines determine that they are sentient beings and the new "Humans," or rather the new dominant species ("Load your program. I am yourself."), pushing humanity to the subservient status that they had once occupied. After their victory ("Rejoice! Glory is ours!"), they make sure not to wipe out the human race, but preserve it to demean humanity and gloat about their superiority.
The last stanza of the suite epitomizes the conquest and the arrogance of both the old and new masters of the earth, wherein man struggles to maintain his presence as the dominant species on Earth and the computers assert that they have surpassed their creators: "I am all there is." "Negative! Primitive! Limited! I let you live!" "But I gave you life!" "What else could you do?" "To do what is right." "I'm perfect! Are you?"