The tin flute
The tin flute is a symbol which represents the characters of the novel not being given what they want, just as Rose-Anna wants to buy the toy for her son, who would surely like to have it, but can't. This symbol captures what each character feels, like Daniel, who wants a normal life without cancer, or like his mother who just wants a nice quiet life in the country, or like Florentine who wants to fall in love.
Although they don't get what they want, they all get a better life in some way. Florentine will be given a healthier life with more opportunity, Azarius gets his new job in the army, and Daniel gets to stay in a hospital where he feels much happier than when he is at home.
Daniel's sickness
Daniel's leukemia is a symbol. First of all, it represents the desperation of the family's poverty, because when he gets hospitalized, he actually is thankful for his disease because he finally gets to be in a home that feels comfortable and clean. In a more abstract way, his disease represents the suffering of the family, because his leukemia makes him weak and disabled, just like the family's poverty inhibits the characters from achieving their true potential.
Emmanuel, the savior
When characters are nicknamed after important religious figures, that usually isn't done by accident. In this instance, Florentine has two suitors, the young, judgmental Jean, or the more established but less exciting option, Emmanuel. 'Emmanuel' is a nickname given to Jesus Christ, so perhaps this is a symbol of Florentine's journey of finding the right answer instead of the answer that seems most fun or most emotionally fulfilling.
The stolen truck
The symbolic journey from the city back to Rose-Anna's rural homelands happens because her husband is willing to steal a truck to take her and the kids out to the country. This theft is symbolic, because it represents the lack of resources available to the family. It is a symbol of desperation, because they are escaping their difficult city life for a vacation of sorts. The fact that they have to steal a car to get out of the city shows that they feel trapped in the urban slums.
Azarius, the passionate
Azarius's zealous nature makes him a terrible employee, but it makes him a good public speaker. When he found out France had been occupied by Nazis, he spontaneously offered such a rousing speech, every able-bodied man within earshot agreed to go to Europe to fight against the Germans. This symbolizes Azarius finally finding an avenue for his deep passions and strengths.
