What is the purpose of the opening chorus in romeo and juliet?

This opening speech by the Chorus serves as an introduction to Romeo and Juliet. We are provided with information about where the play takes place, and given some background information about its principal characters.

The obvious function of the Prologue as introduction to the Verona of Romeo and Juliet can obscure its deeper, more important function. The Prologue does not merely set the scene of Romeo and Juliet, it tells the audience exactly what is going to happen in the play. The Prologue refers to an ill-fated couple with its use of the word “star-crossed,” which means, literally, against the stars. Stars were thought to control people’s destinies. But the Prologue itself creates this sense of fate by providing the audience with the knowledge that Romeo and Juliet will die even before the play has begun. The audience therefore watches the play with the expectation that it must fulfill the terms set in the Prologue. The structure of the play itself is the fate from which Romeo and Juliet cannot escape.

im gonna take a guess and say gas vans and chambers

i would say that these are the two thesis statements best for a literary analysis essay on recurring themes in shakespeare's romeo and juliet:

1.  in romeo and juliet, shakespeare demonstrates that love comes in a variety of forms, be it romantic, familial, or between friends.

2.  shakespeare explores the struggle for identity through the character of juliet in his play romeo and juliet.

the other theses aren't reoccurring in this play. 

explanation: