Triple-A strikes chord with disenchanted listeners

One musical voice gaining ground on public radio sounds a little scruffier than the rest. Rather than a viola or sax, it bears a six-string axe and a heavier backbeat than your average chamber ensemble. Triple-A, an eclectic format that blends rock, folk, blues, world music and other genres, has already proven popular and lucrative for stations such as New York’s WFUV, Philadelphia’s WXPN and southern California’s KCRW. But smaller stations in fly-over country, inspired by the format’s major-market success, are also displacing jazz and classical music for newer musical genres that carry themselves like outsiders. As a result, listeners may be tuning in to the sultry lilt of young chanteuse Norah Jones or the twang of O Brother blues rather than Mozart and Gershwin.