Look Dear, they're playing someone else's song!
While I was working at the Airport in Hawaii years ago, I decided to learn Japanese, so that I could welcome visitors off the plane from Japan in their native language.
After struggling for one semester at the University in Japanese 100, I finally opened the door to a plane arriving from Japan, and drawled "Oh-oou Haii-yoou go-ou zaiiii maaas."
The Japanese passenger, first off the plane, politely apologized to me, in halting English, saying that he didn't really understand English. He didn't even recognize my drawling Japanese as being Japanese! It was back to the “drawling” board for me.
The child is actually working on this difficult problem of prosody (rhythm) from the day he/she is born. Studies have shown that when a language is being spoken around an infant, that infant will be moving in unison with the rhythm of the language--kind of like dancing.
From personal experience, I know that once I have danced to music, it becomes more meaningful. Of course, my wife say's that once I have danced to music, it becomes agonizing, but she only said that in an emotional state after her foot surgery.