Why does steinbeck make reference to the songs in every chapter of "the pearl"?

Excerpt from saving the thrift store: a dramalee washington2rosa: eddie, i don’t recognize the shirt you’re wearing. when did you get it? 3louis: it doesn’t look as disheveled as the soccer shirts you wear all the time.4eddie: well, i’m not going to tiptoe through the soccer field to keep my clothes neat. (louis playfully aims a soccer ball at eddie. rosa deflects it.)5rosa: what i was trying to say is that the shirt looks really good. (louis wanders over to the morning newspaper that is still sitting on the front lawn. he leafs through it while eddie and rosa talk.) in line 5, which point is rosa making when she says eddie’s shirt looks good? a) the store must have new merchandise. b) rosa is jealous of eddie’s new shirt. c) eddie must have done his own laundry. d) eddie often wears old, tattered shirts.