He mentioned how he reacted to his brother's death and described Allie personality and how much he loved him. After finishing the composition he went over to the window to kill time until he got tired.
Chapter 6.
In the sixth chapter Holden sits in his room until Stradlater comes back. He is very worried about Jane and if Stradlater has treated her badly so he starts asking as many questions as possible about where Jane and Stradlater went and what they did. Stradlater's playfully hitting Holden a couple of times irritated Holden who tried to hit him back. He missed though and the entire incident made Stradlater quite angry so they got into a fight. Due to the fact that Holden was not as strong and Stradlater was probably a lot more used to picking fights because of his personality, Stradlater didn't get hurt but Holder ended up with a bloody nose. Stradlater was left worrying about the consequences of his actions.
Chapter 7.
Holden goes into Ackley's room and talks to him for a while. Ackley is sleeping though and gets a little bit irritated. Holden asks Ackley if he could spend the night in Ackley's roommate's bed since he is away for the weekend. Ackley is not too comfortable with it but Holden reassures him that he will leave after a while. Holden cannot stop thinking of Jane and Stradlater. He tries to wake Ackley, who has fallen asleep, up, but that just irritates him and so Holden leaves the room. While sitting in the hallway of the dorm he decides to leave for New York that same night instead of waiting until Wednesday when he is supposed to go home. He plans on staying in New York for a while before actually going back to his parent's apartment so they can take in the news of his expulsion then.
Chapter 8.
In the eighth chapter, Holden walks to the train station and catches the first train there is to New York. When the train reaches Trenton station, a very attractive older woman happens to sit next to him.