I wish I had a better microphone on my camera, but the weirdest thing wasn't the sheer number of crows that all decided to hang out at once (though it is the biggest murder I've seen downtown), it was the strange way they kept alternating back and forth between regular crowing and cawing in unison.
Which I gather isn't a new thing. According to the always reliable internets, they supposedly like to do it when a storm is coming. And considering today was the first day of rain we've had all year, they've probably been saving up that angry corvid energy for quite a while.
It's now about an hour and a half after I shot the video, and I can still hear them out there... circling overhead... in the darkness....