Though Walter Hopps has not worked at a Washington museum for 14 years, his name still carries a certain magic here. During his tenures as Corcoran director (1967-1972) and curator at the National Museum of American Art (1972-1980), Hopps’ self-assurance permitted him to consider relatively unknown contemporary Washington artists on a par with those already validated by the national art press. In so doing, he exerted a powerful influence on Washington art and helped advance the works of several now internationally recognized artists, including Sam Gilliam and Gene Davis. Hopps, who left D.C. in 1980 to direct Houston’s Menil Collection, lectures on another Washington legend, 83-year-old Jacob Kainen, whose retrospective opens at the National Museum of American Art this week, and whose distinguished career represents a virtual summary of 20th-century American painting. Friday at 6:45 p.m. at the Corcoran Gallery of Art, 17th & New York Ave. NW. FREE. For reservations call (202) 785-1144. (Rex Weil)