New choral groups and small ensembles keep springing up, but the 18-year-old Washington Chamber Orchestra may have sounded its last note. Financial problems have forced cancellation of tonight's concert in the Kennedy Center's Terrace Theater. An April concert featuring the two winners of the International Bach Competition also is in jeopardy.

Paul Teare, an orchestra board member and WGMS program director, had warned concertgoers at a performance last month that the concert they had just heard might be the last one given. He cited a growing deficit and shrinking funding, and said that ticket subscriptions could not possibly keep the group solvent.

"The orchestra cannot begin to cover its costs . . . It is in the position of not being able to pay its own way," says board member Peggy Miller. "A lot of organizations prefer to give to groups that are just beginning, as the orchestra was years ago. We have trouble finding large corporate sponsors in Washington. Corporations in Washington will give $1,000 to $2,500 tops. Before, we were getting $10,000 a concert."

Paradoxically, it is the group's success that may have caused its undoing. The 22-member orchestra was a part of a cultural renaissance in Washington in the late '60s, when it first began performing free concerts at the First Baptist Church, at 16th and O Streets NW. Funding came from a variety of charitable organizations and the District government. As the Chamber Orchestra's popularity grew, so did audiences; it soon needed a larger performance hall.

With a bigger audience -- one that the board and funders felt could afford ticketed concerts -- the board decided that the orchestra could raise its own operating funds through ticket sales. The orchestra moved to Ford's Theatre in 1981, and soon after to Lisner Auditorium before finally settling at the Kennedy Center. While the costs at the Kennedy Center were not much more than at Lisner, the "ticket appeal" was much greater, says Miller. Nevertheless, the orchestra may go under.

Delaware on Display

Old Delaware houses seem to be the display item of choice in Washington's museums. At the National Museum of American History, a Revolutionary War-era house is on exhibit in the museum's "After the Revolution: Everyday Life in America, 1780-1800." Meanwhile, over on Judiciary Square, the National Building Museum staff awaits the arrival of the Governor John Cook House from Smyrna, Del. It is to arrive Saturday, by flatbed truck, and will repose in the museum's Fourth Street parking lot.

Lest the public be confounded, Building Museum officials explain that their interest in such houses differs from the Smithsonian's.

"We are emphasizing the architecture and the construction methods," says Karen Montgomery, director of public programs, "not the sociology."

At one time, American History curators considered obtaining the Cook House but then decided against it. A thoughtful developer, made aware of the Building Museum's existence, donated it to the museum.

The house was built by colonial politico John Cook, who was later appointed state governor. It is a gambrel-roofed structure, constructed of planking that makes it look like "a more elegant version of a log house," says Montgomery. Though it was built in the 1770s, "it is in the vernacular style of a century earlier," and tells more about building styles and methods of the 1670s, she says.

Restoration will be conducted under the auspices of the National Preservation Institute. But the work on the house will be done by the general public: Museum officials hope people will sign up to take building restoration classes that will involve working on the house. "The restoration will take longer," says Montgomery, "but . . . one of our goals is to educate the public in the building methods of the 18th century."

USA for Africa's Ledger

USA for Africa, the organization that put together the "We Are the World" album, announced Saturday in its first annual report that by Jan. 31 it had earned $44.6 million from "direct public support, record royalties, interest and other sources." The report said that $19 million has been spent so far on "immediate African relief." USA for Africa's board of directors has committed another $24.5 million to "long-term African recovery and development projects." The organization also reported that $900,000 has been spent on "health, hunger and social programs" in the United States.

End Notes

The D.C. Commission on the Arts and Humanities has named 14 Washington writers, artists, musicians, dancers, filmmakers and actors to its 1986 artistic residencies in the public schools . . . Hiram W. Woodward Jr. has been appointed first full-time curator of Asian art at Baltimore's Walters Art Gallery . . . The National Endowment of the Arts announced $5.9 million in opera and musical theater grants to 172 organizations for the current performance season: The Washington Drama Society at Arena Stage received $20,000; Washington Opera, $142,500; American Symphony Orchestra League, $130,150; National Institute for Music Theater, $160,000; Opera America Inc. received three grants totaling $235,000.