The Greek Chorus

Paula Vogel uses a Greek Chorus in "How I Learned To Drive". Here's a definition (courtesy of Wikipedia) of what it is:

In tragic plays of ancient Greece, the chorus (choros) is believed to have grown out of the Greek dithyrambs and tragikon drama. The chorus offered background and summary information to help the audience follow the performance, commented on main themes, and showed how an ideal audience might react to the drama as it was presented. They also represent the general populace of any particular story. In many ancient Greek plays, the chorus expressed to the audience what the main characters could not say, such as their fears or secrets. The chorus usually communicated in song form, but sometimes the message was spoken.

How does it work/not work in Vogel's play? Opinions?