May in Philadelphia doesn't arrive so much as settle in. The light stays longer. Windows that were closed all winter are open again, and you can hear what people are listening to from the street. Galleries fill up earlier in the evening. Basement shows run later. The calendar gets crowded with the kind of nights that don't advertise themselves but tend to stay with you. What follows isn't a complete guide to the month, only the things we found ourselves drawn to: a few rooms, a few screenings, a few stages. Some of the names will be familiar. Most, we hope, won't be.