Beyond the pan flute troupes tootling Simon & Garfunkel and the panhandlers singing Van Morrison, there's a tier of subway musicians who make noise because that's where their potential audiences are. The longest-running underground engagement belongs to the OCTOGENARIAN WOMAN WHO HANGS OUT ON GRAND CENTRAL'S NO. 7 PLATFORM at night—she's not there all the time, but she's been putting in regular appearances for at least 11 years. Sometimes her repertoire is grand opera; occasionally she throws in a show tune, which she belts out with Ethel Merman-esque brio; more often, these days, she just hangs out by the stairwell and watches people.