What sound does Shasta hear for the first time in Chap. 9?  

He heard a sound from a nightingale which he had never heard before.

What might that symbolize in the story?  

They went out of desert to a valley, the night was so peace that the children and the horse were fast asleep.

What more do we learn about the character of the horses in this chapter? 

Bree: arrogant, some little selfish , don’t will to help others, impolite.

Hwin: a little shy but brave, she have a strong and self-control spirit

Which horse seems more courageous and noble than the other?  Why?

Hwin seemed more courageous and noble. Like mentioned in chapter 9, when Bree crushingly replied her, she was very well-bred and didnot retort him even if she was right. She was like a very nervous and gentle person who was easily put down. From her words, she was also self-controlled and she didnot lost the power of forcing herself even though she were free. And though she was weaker and more tired, she still set the pace.