The siren was the first sound you learned to ignore on the Lower East Side. Not because you did not care. Because you could not afford to care every time. The sirens came every ten minutes. Fire truck. Ambulance. Police car. Each one somebody's worst day arriving at speed. You heard the siren start six blocks away and you tracked it with your ears the way a dog tracks a squirrel. Getting closer. Getting louder. Getting personal. And then it passed you and kept going and it was somebody else's emergency and you went back to your coffee.

The siren was a Doppler shift you could feel in your teeth. High pitch coming toward you. Low pitch going away. The physics of somebody else's crisis changing frequency as it moved past your window. You lived inside a physics experiment and the experiment never ended.

The tourists flinched at the sirens. Every time. The siren came and they stopped on the sidewalk and looked around like something was about to happen to them. Nothing was about to happen to them. Something was happening to somebody else six blocks in the direction the siren was going. The tourist heard danger. The local heard Tuesday.

The old woman on the third floor kept count. She told me she heard forty-seven sirens on a Tuesday in August. Forty-seven emergencies in one day on one block. I asked her how she knew it was forty-seven. She said she had nothing else to count. Her husband had died in March and she counted sirens instead of the days since.

I played guitar on the corner and the sirens were my backup band. They came in without rehearsal and left without applause. The siren did not care about my set list. The siren had its own set list and its set list was somebody's chest pain, somebody's kitchen fire, somebody's boyfriend with a knife. The siren was the most honest musician on the Lower East Side. It only played when the gig was real.

You learned the difference between the sirens. The fire truck had a low moan that shook the windows. The ambulance had a high yelp that cut through traffic like a blade. The police car had a whoop that sounded like a question nobody wanted to answer. Three instruments. Three emergencies. One orchestra. No conductor. The Lower East Side was the concert hall and nobody bought a ticket.

The siren faded and the block went quiet for nine minutes and then another one came. The silence between sirens was the closest thing to peace the Lower East Side ever offered. You did not notice the peace until the next siren broke it. That is how peace works. You only hear it leaving.