WORTH NOTING ON TV
This guide is designed to alert readers to the scope and variety of programming coming up. Listing is not meant to represent blanket endorsement. Viewers are urged to be selective. FRIDAY
Bach's Brandenburg Concertos (PBS, 9-11 p.m.): Repeat of two ``Great Performances'' featuring Nikolaus Harnoncourt and the Concentus Musicus of Vienna.
SATURDAY
Evening at Pops (PBS, 8-9 p.m.): An evening of song with guitarist Liona Boyd, Cee-Threepio, Artoo-Detoo, Leontyne Price, the King Singers, and Bernadette Peters. John Williams conducts.
A Prairie Home Companion (PBS, 9-11 p.m.): Repeat of special with American Public Radio's humorist Garrison Keillor, who tells tales about mythic Lake Wobegon, Minn.
SUNDAY
Ducks Under Siege (PBS, 8-9 p.m.): This National Audubon Society special reports on the loss of US wetlands and subsequent decline in duck population.
National Geographic Explorer (WTBS/cable, 9-11 p.m.): Short documentaries suitable for the whole family.
Between Two Women (ABC, 9-11 p.m.): Repeat of memorable character study of two dissimilar women played in all their complexities by Colleen Dewhurst and Farrah Fawcett.
Carole King: One to One (Arts & Entertainment/cable, 9-10:30 p.m.): This singer-songwriter remembers a life full of memorable pop music.
MONDAY
Charlie Chaplin, Parts I and II (PBS, 9-11 p.m.): Repeat of ``American Masters'' programs that chronicle the early years of this comic genius.
Special Olympics Opening Ceremonies (ABC, 9-11 p.m.): All-star gala with hosts Barbara Mandrell and John Denver heralds the beginning of the Seventh Internationmal Summer Special Olympics at Notre Dame Stadium in South Bend, Ind.
TUESDAY
A Continent Crucified (PBS, 9-10 p.m.): Segment of ``South American Journey'' explores church competition in South America and the current activities of Mormon missionaries.
WEDNESDAY
Star Wars: The Bottom Line (PBS, 9:30-11 p.m.): The economic consequences of the Strategic Defense Initiative are explored by the Press and the Public Project.
Living Dangerously: El Matador (Arts & Entertainment/cable, 9-10 p.m.): A Mexican teen-ager prepares for his first bullfight.
THURSDAY
Our World (ABC, 9-10 p.m.): One of 1987's best series, now doomed, repeats the program that surveyed the summer and fall of 1952. Linda Ellerbee and Ray Gandolf are hosts.
Listings are in Eastern time; other zones may vary. Please check listings for all PBS programs, since local option often results in differing days and times.