Western artist Alexandre Hogue's works are on view in a small retrospective, "Nature's Forms/Nature's Forces," at the National Museum of American Art through Nov. 3. Hogue keeps camp with artists Grant Wood, Thomas Hart Benton and the Taos School, but although his work is colorful and competent, it seldom surpasses these artists' efforts. DANCE

Mixed in with other arts festivities and entertainment, there'll be numbers of free dance performances available at this year's Add Arts festival today (rain date Monday) between noon and midnight, at various locations between Seventh and Ninth streets, along F Street NW, adjoining the Martin Luther King Memorial Library. Such troupes as the Ava/Teri Dancetheatre, Roberta Rothstein and Dancers, Davis Center Dancers and African Heritage Dancers and Drummers will be among the participants. For more information call District Curators Inc. at 783-7898. POP MUSIC Scottish singer Archie Fisher, one of the most popular members of that country's greatest family of singers, makes a rare club appearance at the Birchmere on Tuesday.

Talk about rough and rowdy ways: Hank Williams Jr. carries on the family name, if not the same vibrant country music, at the Merriweather Post Pavilion on Friday.

Green on Red may top Saturday's bill at the 9:30, but rock aficionados won't want to miss the opening act, Alex Chilton (the Box Tops, Big Star).