Family is going on a road trip and need to stop for gas
Parents go into store
The two kids are sitting in the back seat yelling at each other and crying the entire car ride about being on each other's "side".
Parents buy 2 symphony bars each
The parents are already frustrated having to drive a car this long, so the kids being loud and annoying is angering them and making them miserable. They are trying to figure out anything to make them stop, but not matter how much they yell at them the kids continue to fight.
Parents return to car in bliss eating chocolate
The kids are not allowed to go into the gas station because the parents need some peace and quiet, and they are desperate to try to find something to give them some kind of relief.
The parents scan the aisles and come across the Symphony Bars. They read the description not knowing anything about it and decide to make the purchase.
The parents return to the car while the kids are still fighting and open the chocolate bars. Once they take the first bite, very peaceful symphony music starts playing and completely drowns the kids out. They close their eyes and are in complete bliss.