His parties are magnificent. They are held under canvas tents in his garden, his bars are always stocked with the best of liquors, he has buffet tables with everything you can imagine. The book says that his parties are almost like a carnival. All though the book describes the parties so well, we never hear about the host of them. And the people that are there do not even know about the host. He is never at the parties.
Towards the end of the chapter, we get our first meeting with Gatsby. It occurs when Jordan and Nick go outside to get away from the party. Nick describes Gatsby as being a "elegant young roughneck" and being "a year or two over thirty". The way that Nick describes Gatsby makes Gatsby stand out from all the other characters in the book. He is a step above the rest of the characters, even Tom Buchanan who is from East Egg where the "old rich" live. This technique is used so that it seems that Gatsby is really this great rich guy, but then it comes crashing down when we discover his real past. .
Chapter 4 is the first time in the book that we actually get a glimpse at his past. Nick and Gatsby take a drive to New York and Gatsby decides to tell Nick a little about his past. Gatsby says that he is from wealthy people from the Midwest, that are all dead. He claims to be educated at Oxford. Then when Nick asks from what part of the Midwest, Gatsby responds with "San Francisco". That is a hint right there that there is something fishy about his past. We also learn about Gatsby's infatuation with Daisy in this chapter. We hear the story from Jordan, during a conversation her and Nick have. Right here, we learn another important part of Gatsby's past. This plays a major role in the story because it reveals a soft spot in the great man's life. This is an important part due to the fact that we see Gatsby as a filthy rich guy, that can have any girl he wants, but yet he is hooked on a married woman.