The beauty of being startled

So it turns out that most babies are born with a startle reflex (or a Moro reflex, for you experts out there): when they hear a sudden, loud noise, they extend their arms, legs, and fingers, arch their back, and draw their head back, before finally drawing their arms back into their chest. It's really kind of neat to see: something like an anemone tackling a careless tropical fish, and then retreating for a meal.

Cleo seems to be used to the occasional crash of trucks hitting potholes on Falls Road, but today it was a passage in Mozart's Eine Kleine Nachtmusik that snuck up on her while she nursed. A sudden surge in the dynamics, and that was that: baby's limbs everywhere for a wild second or two.

Thinking about it afterwards, I remembered that my dad, when he's listened to pop tracks that I've sent his way over the years (hoping for his stamp of approval on that latest Pearl Jam song or Eminem tune), has occasionally mentioned that they don't have many interesting changes in volume. It's just full intensity, for three or four minutes, where he's used to the more extended compositions of classical composers, who often (perhaps because of the length of the piece) alter moods more often, and more fully. There must be exceptions, of course, and my dad certainly didn't mean it as a rule - but it is an interesting observation, and it leads to an implicit thought experiment, which I'll simply pose to anyone who's reading: can you think of pieces that feature dramatic shifts that are sudden enough to trigger the Moro reflex?