It's important that mother and child are simpatico. That if one's needs are being fulfilled, the result flows on to the other.
And that is why in our house music is important. If someone's happy rocking out, usually the other is happy to rock out to it. There is only so much enthusiasm one can muster for rousing renditions of The Wiggles 'Fruit Salad' sung over and over. And over. And over. And over once more for good luck.