To the left on your radio dial

Enter Central Air, scheduled to hit the airwaves as early as March. Its masterminds say it will be tailored to appeal to people with MoveOn.org politics who crave Rush Limbaugh-style bite. Less earnest than National Public Radio and not as strident or suffused with the victim/oppressor paradigm as Pacifica, it will bring a populist, late-night-television sensibility to radio.

When it launches in March or April, it will broadcast 14 to 18 hours a day, seven days a week, on stations it is buying -- or whose airtime it will lease -- in major cities like New York, Los Angeles, San Francisco, Philadelphia, Miami, Pittsburgh and Boston, says Mark Walsh, the chief executive officer of Progress Media, which he co-founded and which is the parent company of Central Air. "In division, there's a media opportunity," Mr. Walsh continues. "In a divided nation, at least there are opinions, information which takes a side."