The Chorus in Marlowe's Dr. Faustus, the inspiration for Goethe's Faust Parts I & II, serves two purposes. First, it is transitional and, second, it is expository. The first purpose of the Chorus is to provide transitions into and/or out of elements of the play, reminiscent of Greek Choruses.
The second purpose is to provide enlightenment into Dr. Faustus's behavior and character in addition to giving the audience information that Faustus himself doesn't have, thus serving in a prescient and foretelling capacity. The objective of the Chorus's function is to increase suspense as the audience moves through the saga with Dr. Faustus.
FOR EVERY PLAY A CHORUS IS A DEVICE THAT CONVEYS EVENTS THAT TAKE PLACE OFF STAGE IE:EVENTS THAT CANNOT BE ACTED OUT ON STAGE.IN DR FAUSTUS TOO THEY SERVE THE SAME PURPOSE FOR EXAMPLE THE GROWTH OF FAUSTUS FROM A CHILD TO A SCHOLAR CANNOT BE ACTED OUT ON STAGE.ON THE OTHER HAND,THE SPECTATORS WONT BE IN A POSITION TO GRASP WHAT IS HAPPENING ON STAGE IF SUDDENLY FAUSTUS APPEARS AND SITS IN SOLILOQUY.SO THE CHORUS HELPS BOTH THE AUDIENCE AND THE ACORS TO SETTLE DOWN AND GET COMFORTABLE WITH THE SITUATION.IN OTHER WORDS IT PROVIDES A LINK BETWEEN THE AUDIENCE AND THE PLAY.THEY HELP IN BETTER UDERSTANDING OF THE PLAY.