Hetaira (Hetaera) in Ancient Greek Symposim

This essay’s focus is on the Hetaira’s Role in Ancient Greek Symposium. (I just want to emphasize that these are symposiums of Ancient GREECE and not those of Ancient Rome; be careful when finding sources!) You may want to talk about the symposium and give an overview of it so the reader can better understand what role she (the heitaira) plays. I have included the instructions and guidelines of the paper. (Please read.)

Regarding sources:
Please use documented, scholarly sources. In other words, Wikipedia and blogs do not count.
The sources required to use are primary, such as from ancient writers, inscriptions, or archaeological evidence. Though you are free to use additional sources, please use [Athenaeus, Book 13] as it is extremely relevant.
*You might want to find the translated version since it is written in Greek.

A source that may be useful to reference and read:
Lucian (Volume 1) by A.M. Harmon. Use only the last section: THE CAROUSAL, or THE LAPITHS.

Also, websites of information that may be useful: http://penelope.uchicago.edu/~grout/encyclopaedia_romana/greece/hetairai/hetairai.html.
http://depthome.brooklyn.cuny.edu/classics/dunkle/athnlife/hetaira.htm
http://en.wikipedia.org/wiki/Hetaera