If you see the wives of two congressmen and a senator strolling around with Sony Walkman sets attached to their ears, chances are they're listening to the sounds of the Washington Chamber Orchestra.

Last night, at a dinner dance following the orchestra's opening concert of the season, the Walkman portable stereo players were presented to Nancy Thurmond, hostess and wife of Sen. Strom Thurmond (R-S.C.), and to co-hostesses Tricia Lott, wife of Rep. Trent Lott (R-Miss.), and Suzanne Dicks, wife of Rep. Norman Dicks (D-Wash.).

"So you can have chamber music wherever you go," the three organizers were told as they also were given tapes of the orchestra in performance.

The $100-a-plate dinner at the Hotel Washington drew 250 supporters of the chamber group after the orchestra began a new season at Ford's Theatre. During this season WCO managers hope to lay the groundwork for expanded programming and a larger audience.

Last night's performance before 650 at Ford's was the first of the WCO's new "subscription series." The chamber orchestra, with 20 or so strings with varied complement of brass/woodwind/percussion, was founded in 1968 as a semi-professional group of free-lance musicians. Through the years, it has given free concerts at Washington's First Baptist Church, where Alvin Lunde, the founder and director, is organist and choirmaster.

The benefit gala last night was a fund-raiser for the orchestra as it takes steps to become a more visible presence on the Washington cultural scene.

The Thurmonds brought their two daughters, Nancy Moore, 10, and Julie, 7, to the concert, and Mrs. Thurmond later told Timothy Baker, the concertmaster: "I never heard a peep out of them during the concert. I can't imagine that happening before."

Baker came to the dinner with his violin case under his arm. He checked his coat -- but not his violin, an Italian instrument made by Pressenda and dated 1837. He carried it with him to the table.

"It's something you don't check at the cloakroom," said the New York musician.