Say what you will about rain pouring down for hours on a free outdoor concert with no roof over the audience: It quickly separates the casual looky-loos from the dedicated attendees. For proof, look no further than the Saturday evening program for the inaugural Boston Summer Arts Weekend. The weather may have chased away the bulk of the crowd by the time the two closing acts took the stage, but a small, committed (and wet) crowd remained in Copley Square to cheer them on.
Had the weather held up, Suzanne Vega’s announced plan to play the entirety of her 1987 album “Solitude Standing” from start to finish might have been an odd fit for a festival crowd. But the diehard fans who endured the rain turned out to be the ideal audience for a setlist meant to appease diehard fans. With her two biggest hits — “Tom’s Diner” and “Luka” — dispatched right away, Vega burrowed into the lesser-known songs that make up the rest of her breakthrough record. She estimated that she hadn’t played some of them, like “In the Eye,” in 25 years.