When was the last time you did something sweet for your favorite singer-songwriter? Not ditching your copy of Dylan's Under the Red Sky doesn't count. Neither does leaving a rambling mash note on Nelly Furtado's fan discussion site. We're talking subtle kindness, selfless gesture -- something a judge wouldn't say violates your restraining order. Take, for example, the donation that some of Patty Griffin's fans made to the Committee to Abolish Landmines in her name to honor the singer's recent birthday. "I don't know how I got to be such a lucky forty-year-old," Griffin responded on her Web site. "You've given me the perfect gift. Thank you. I'm blown away again." OK, that last phrase probably wasn't the committee's ideal expression of gratitude. But unintentional explosion humor aside, Griffin is one of the sharpest lyricists working -- just ask the Dixie Chicks, whose cover of Griffin's "Top of the World" gave their most recent tour its name. That song appears on Griffin's beguiling new Impossible Dream, a quiet, rainy album that lingers like a low cloud. And now she's finally coming to the area for the first time. Be grateful.