You ask what makes the dolls sing. I'm not sure of the why, but I understand the how.  I've seen it, and it's beautiful, and it breaks my heart. It requires only that they remove their heads.
     As you know, the heads are empty. And so the singing comes from the emptiness at the base of the head, like wind blowing over the neck of a bottle. I can't say where the breath comes from, but it always comes.
     The heads rest in the dolls' laps, the heads upside down and tilted, eyes curtained, hands across the lips and the two painted teeth to preserve the tilt. Girls learn the tilt of the neck and pelvis. Like this. Move your hips like this. As long as there is a critical mass, the singing continues. It rises, falls and twists in the air, peppery and sad.
     It takes place, this singing, in the grotto of the church. They sit in a circle around what was once the baptismal pool.

We have long lived in a place where water shapes the topography of the land from underneath the surface. We float on a limestone sponge where most of the drama goes on beneath the ground. Dangerous roaring rivers, unmapped pirated streams, caverns filled with water, endangered blind albino cavefish. The grotto reaches down deep into a lost river that starts as ooze in a meadow and ends up as a tributary of the Mississippi. The river begins as a trickle of acid rain in the meadow's low regions. It eats its way into cracks in the limestone like a crack in the tooth. A cosmic ooze.
     Outside of town there's a bit of river at the surface, amber and chartreuse. And then a swallow hole where the thirsty limestone gulps in the river, the hole a swirling pit of mud and debris. Here the river loses itself, disappearing underground. Right before it goes under, there's a timber raft that looks like a solid raft of logs and sticks that you could walk across but which in fact is an illusion. Step on a timber raft and you will disappear. We've lost both cows and children.
     Like an aneurism, the river appears again in the form of a spring at the base of the grotto. Like a swimmer, it takes a breath then dives underground again. Children were told that if they weren't very very good that the grotto would swallow them on the day of their baptism.
     The grotto is shallow. Imaginative children see their faces rise up out of the pool when they lean over it. It frightens them as the singing dolls now frighten them. The dolls' long hair like seaweed.  Some of the dolls are mothers. All of them are children. Their singing sounds like whale song, the eerie trilling somewhere between human anguish and joy.

It's easy to remove the heads, harder to lift and reattach them when the singing's over. They all attempt to replace their own heads, with varying success, and so they help each other like bridesmaids, arranging the veils of hair over the knees before the singing begins and helping place the head carefully on the neck stem when it's done. Before they begin their walk back out to the street, the eyes look forward and the hair is pushed back once again from the face.  
     Their eyes say Don't let anything slip out as the head is replaced: a secret lover's name, a theft, the memory of a stillborn child, the rape you didn't know was rape until later, things you couldn't tell your mother when you were a girl, the justice that could have been yours had you spoken then, had someone listened.
     I am a mother of a girl who is now a doll, and I too was once a girl. Oh please forgive me for not speaking or not listening, for not intuiting. I cannot join you. I cannot save you. Cover the mouth, remove the head, wait for the air itself to pull it out of you. I know that in addition to the emptiness, your head has contained razor wire and string, needles and cracked glass.  It requires care when unattached. You would not want to put your hand inside and rummage for seeds like you would a pumpkin. And at the end you want the head to reattach so the eyes can show a bit of blue or green, the spinal cords double knot to the brain stem, the legs move with purpose. There are times, yes, when you want to carry the head or put it on a shelf and be done with it, but there are other times when you want to form a choir.
     I know that it feels good when the head and body go their separate ways. And sometimes the sound is so surprising it knocks you out.  You sound like an angel when the wind blows across your cut throat.  You feel as though you could fly.
     So that, I suppose, is the why.

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"Grotto" is one of an in-progress collection of stories about drug-addicted dolls in southern Indiana. Another story in the series has appeared in The Southwest Review, where it won the McGinnis-Ritchie Prize. One is forthcoming in The Collagist.