NATURE REVIEW
Seventeen summers ago I was hanging out in Iowa City, sweating through grad school, and too engrossed in my work to care much about the periodical cicada invasion of Brood 13. Now that I am living through their ear-wrenching re-emergence up close in Chicago, I'm marveling that I couldn't hear them back then, even from 200 miles away across a state line.

I spent years, mercifully less than 17, at the University of Iowa learning to analyze music-specifically sound and how composers organize it. Fine-tuned hearing is what a musician has to develop to prepare for a profession of listening. Careful listening is what musicians are all about. Ask us to tune out a sound and we can't do it. Ask where a pin dropped, and we'll be proud to tell you we heard it.

Now that a slew of cicadas has taken over the northern Illinois soundscape, even drowning out my neighbor's annoyingly loud weed-eater, I've taken to analyzing this new surround-sound. Early each morning, they wind up with a steady drone, hovering around E-flat, at about 1350 cycles per second. That's not too far from the top of a piano if you want to check. Within an hour, they crank it up a half-step to E. Maybe it's their caffeine routine, or perhaps simply the sun warming up the air.

Their morning timbre is hollow and brittle, like a mallet hitting a xylophone. If they worked at this great symphony in the trees with a master, they could surely wake us humans up with a bit of a rounder, mellower tone quality. Tone color aside, I give the little chirpers high marks for tuning, as the whole choir never seems to waver far from their home around 1400 hertz.

But there are other musical elements such as dynamics and rhythm. Boo on both counts, unless you want to praise them for consistency-like the never-ending tape loops favored by the Minimalist composers of the '60s. Their whining away has a machine-like predictability, whirring at one volume and one very fast speed, without any nuances. In cicada singing, I hear the sameness that is so irritating about those cheap, singing greeting cards: No sense of attack, growth, and decay in their sound, no rhythmic vitality to display a sense of invention. Where is the personality that might distinguish one particularly talented cicada from the other millions, or make today's concert (yes, it's an all-day marathon every day, not just two hours with an intermission in between) stand out from yesterday's rehearsal? Not there.

The one variation I have noticed comes on around noon, after those vibrating membranes are good and warm. A second level of sound starts to float below the droning, akin to a creative monk adding a new voice to plainchant back in the Middle Ages. Precisely coordinated against the insecto-xylophones, I hear nature's best imitation of a 26-HP Sears Craftsman, generated entirely without burning fossil fuels, and roaring to a near-painful crescendo which is sustained as if on cue for about two seconds. If you think two seconds is a short time, easily dismissed into yesterday's hourglass, let your ears ring periodically, every two seconds for two hours, and you will long to have the neighbor's son fire up his rock band for auditory relief.

My analysis of the sound of cicadas extends beyond measuring discrete elements like pitch, rhythm, and timbre. At its most basic, sound should deliver a message, just like the sound of a champagne cork flying or a wave crashing, or your mom yelling to stop that, right now. If the sound is organized really well, it should make you think, or reveal something, or better, act as a catalyst to change your mood, or your view, or even better still, your life experience. Does sound touch your soul? When it does, sound becomes more than your kid crying and moves into the realm of art. That's why there are so many different styles of music out there-each one a voice with a point to make.

So, can a throng of four-legged, bug-eyed, winged creatures in a stand of oaks score when it comes to turning sounds into music? For one, the little chirpers have got my attention, which is something great art should do. For days now, I've been thinking about cicadas, marveling at their in-your-face energy and fervor and determination and persistence. Just think of flapping your arms 1,400 times per second from dawn until dusk! Not even a virtuoso violinist can come close!

In their primitive, predictable patter, the periodical cicadas have hit me, not only by brazenly landing unwanted on my shoulders, but by transmitting a message: a spindly 2-inch insect has invaded my consciousness, distracted me from the noise pollution of planes and cars, and made me wish for a treeless prairie with only the occasional peep of a bird or the rustle of reedy grass. Or better yet, their incessant humming draws me to dream of an escape to a really big lake, for example, the one due east, where I could be lulled with the gentle lap of water against the hull of a boat. When sound sends my imagination whirling on flights like that, it really acts like music.

I don't pretend to know much about the scientific process that produces this din. Of course, something moves, just like your vocal folds flap in your throat or a string quivers on a violin, and that motion excites air waves that strike your ears. The entomologists say this is the grinding of rib-like structures in the abdomens of the insects up in trees, simply an artful way for males to find the perfect mate for a sunny summer afternoon liaison.

Aha, boys! Take a cue from the cicadas: Before you're 17, go out and climb a tree! Shucks, climb a lot of them, and learn to sing. Sing really well, really loud, all day long, and don't quit until you catch a girl.

With lessons like that to be learned, maybe we should all be studying music.

Note: If you live beyond the borders of invading cicadas, first be grateful and then go to http://insects.ummz.lsa.umich.edu/fauna/michigan_cicadas/Periodical/Index.html for a sound byte of the insect choir described in detail by John Cooley, David Marshall, and Mark O'Brien. Web page maintained by the University of Michigan Museum of Zoology.