Again dragging an "old" thread up to the top...

We have more tonal sense in English than you'd first think. Have you even been in a church full of people reciting a prayer? There's some kind of common tone (or maybe two, one for men, one for women) that everyone settles down to for the duration of the prayer. You'll notice it if you consciously try to say the prayer in a "normal" voice - you'll stick out like a sore thumb, partly because your pitch doesn't match the group, and partly because prayers are more monotonic than speech.

Another example I like to think of is the notes for "I don't know". If your mouth is full when someone asks you something, you can avoid being rude by sort of humming the correct notes for "I don't know" and they understand you perfectly every time.