Do you want to become a Friend of the Kennedy Center? A new membership is on to double the present 10,000 membership. The Friends, whose chairman is Elizabeth Polk Guest, want to expand in order to increase their support of the Center's educational and public service programs.

Many of the Center's free events such as the weekly symposia and organ demonstrations are sponsored by the Friends, whose volunteers conduct the free guided tours of the Center, staff souvenir stands and handle the specially price ticket program.

With the approaching opening of the Center's new multi-purpose studio theater and recital hall and the new performing arts library, the Friends plan to expand their contributions. Your inquiry, directed to the Friends of the Kennedy Center, Washington, D.C., 20566, will bring you all the information you need.

Issac Stern will be at the Discount Record Shop, 1340 Connecticut Ave., between noon and 1 p.m., Wednesday autographing his recordings.

Jascha Heifetz, the famous violinist, has just established the Heifetz Scholarship Awards, to be given to exceptionally talented violinists for study at his classes at the University of Southern California. Subsidies for living expenses will be included in the awards. For information, write to Dean, School of Performing Arts, University of Southern California, Los Angeles, Calif. 90007.

Oh yes, you must be prepared to play a Bach sonata or partita, one of the big seven concertos, three Paganini Caprices, a work of your choice, and scales in all forms. Heifetz will do the auditioning and make the final decisions. If you're good, it would be worth a try.

Do you want to hear Handel's "Solomon" in Stephen Simon's edition? (Simon is the director of the Kennedy Center's Handel Festival.) Roger Ames will conduct the Montgomery County Masterworks Chorus in "Solomon" at 8:30 p.m., Saturday at Einstein High school in Kensington. Tickets at the door. Soloists include Linda Mabbs, Martha Randall, Beverly Benso, and Talmadge Fauntleroy.

Yo Yo Ma, the cellist who made a stunning impression with the National Symphony under Rostropovich two weeks ago, will play in solo recital on the University Community Chamber Concert Series at 8:30 p.m., Saturday in the University of Maryland's Adult Education Center. Tickets at the door. He is something quite special.

The third concert in the Contemporary Music Forum series playing this year at the Corcoran Gallery will be given at 8:30 p.m., Monday. The program will include Joel Naumman's Trio for flute, violin and harpsichord, commissioned by the Robert Evett Foundation. Other works will be by Lester Trimble, Emerson Meyers, Robert Parris and Nancy Chance. The concert is free.

Howard Bass, lutenist, will play at the Folger Library's free Midday Muse concert on Thursday, beginning at 12:15 p.m. Music by Milano, Weiss, Bach and Dowland.

From America come "Stars of Yerevan," singers and instrumentalists in concert at 8 p.m., Monday in Einstein High School, Kensington. Tickets at the door. The Rotterdam Philharmonic, under the direction of Edo de Waart, with pianist Paul Schenley in the Beethoven Third Concerto, plays in the Kennedy Center, at 3 p.m., Sunday.