I'm going to identify three elements of style and literary devices that Blake uses in the poem, defining each, showing you evidence of each in the poem, and then analyzing its significance in the text.
A correspondence of sounds between words, especially when used at the end of a line in Western Poetry
"I wander thro' each charter'd street, / Near where the charter'd Thames does flow. / And mark in every face I meet / Marks of weakness, marks of woe."
Blake uses the following rhyme scheme: ABAB CDCD EFEF GHGH. Doing so emphasizes the quatrain stanzas, marking a separation between each one. It also creates a sense of anticipation and closure for the reader, who knows the sound of the word coming and is able to conclude each quatrain with the completion of the pattern.
A strong, regular, repeated pattern of movement or sound
"but MOST thro' MIDnight STREETS i HEAR
HOW the YOUTHful HARlots CURSE
BLASTS the NEW-born INfants TEAR
and BLIGHTS with PLAGUE the MARriage HEARSE"
As is particularly evident in the final quatrain, Blake shifts his rhythm around, sometimes employing iambs, a foot with two syllables in an unstressed-stressed pattern, and other times using a trochee, which is a foot whose two syllables are in a stressed-unstressed pattern. By maintaining a degree of similarity, or feet with two syllables, while simultaneously alternating irregularly between trochees and iambs, Blake reinforces the tone of his poem.
The act of saying again something that was already said
"In every cry of every Man, / In every Infants cry of fear, / In every voice: in every ban, / The mind-forg'd manacles I hear"
Blake uses repetition to emphasize the overwhelming nature of his topic, repeating specific words to reinforce its universality or importance.