The New Jersey Chamber Music Society is stepping out for the first time -- out of state, that is, and into the Corcoran Gallery this afternoon. Having recently received a five-year grant of $208,000 from the New Jersey State Council on the Arts, the society can afford to go national.

The council's Artistic Focus Awards are given to organizations with a "realistic ability to achieve national prominence within three to five years," according to council executive director Jeffrey Kesper. "We finally have an opportunity to show that we are not just a stepchild of New York -- the cultural navel of this country," says society executive director Linda Baker, adding that "now we can strut our stuff and show people what we are capable of."

The program, which begins at 5 p.m. in the Corcoran's Frances and Armand Hammer Auditorium, has as its centerpiece a work the society commissioned in 1984 to celebrate its 10th anniversary and the centennial of New Jersey poet and physician William Carlos Williams' birth. Scored for five instruments and a tenor, and based on an epic poem by Williams, "Paterson Songs" was composed by New Jerseyite Loretta Jankowski. Works by such non-New Jersey composers as Brahms and (New Yorker) Katherine Hoover will also be performed.