Four tools Aeschylus uses to build intensity at Agamemnon's homecoming in Agamemnon are Clytemnestra's speech announcing the end of the Trojan War, the conversation between the Herald and the Chorus Leader, the Chorus's song, and the controversy between Agamemnon and Clytemnestra over the tapestries. Clytemnestra's speech builds intensity because she first talks about her mistaken joy over the rumor that the war was over, then follows immediately with her assurance that now the war is won and that Agamemnon is soon to return home: "So wild a cry of joy my lips gave out, / ... / The king himself anon shall tell me all."
This builds intensity because it adds ambiguity and controversy to Agamemnon's reported approach. Intensity is further added through her contemplation of how best to greet him and her protestations of ten years of longing and fidelity:
Remains to think what honour best may greet
My Lord, ... / ... /
Trusty to keep for ten long years unmarred
The store whereon he set his master-seal.
Intensity is increased by the conversation between the Herald and the Leader in which they debate the hazards of the homeward trip and add doubts of Agamemnon's approach:
Say, by what doom the fleet of Greece was driven?
How rose, how sank the storm, the wrath of heaven?
The Chorus follows up with an intensity-building digression into Helen's story and the background of the Trojan War: "Helen, the bride with war for dower / ... / Well named, at once, the Bride and Bane; ...." In addition, they add to the intensity because some of their lines provide foreshadowing that is important to setting up the audience for what is to follow: “The blood-thirst of the lion-race, / ... / And to Fate's goal guides all, in its appointed wise.”
Intensity is further built in Agamemnon's entry speech in which he expresses the controversy between himself and Clytemnestra over the tapestries. This adds to the intensity because it puts them at odds with each other immediately, during the first moments of his homecoming, and provides another source of foreshadowing ("I hold such pride in fear,"):
Not unto me, as to some Eastern lord,
Bowing thyself to earth, make homage loud.
Strew not this purple that shall make each step
An arrogance; such pomp beseems the gods,
Not me. A mortal man to set his foot
On these rich dyes? I hold such pride in fear,
Clytemnestra has rolled out brilliant tapestries that, according to Agamemnon's speech, are the usual province of gods. Clytemnestra claims this is the right way in which to greet her Lord after ten years of battle and Agamemnon insists that he is not fit to walk where gods alone should tred. The intensity built through this controversy moves the plot toward and prepares the audience for the horrific acts to come.