First there was ''Masterpiece Theatre'' on PBS with the best of BBC, mostly for adults. Then there was ''Mousterpiece Theatre'' on the Disney cable channel with the best of ''Mickey Mouse,'' mostly for youngsters.
Now there is ''Minorpiece Theatre'' - as some punsters are calling Wonderworks (PBS, Mondays, 8-9 p.m., check local listings for premieres and repeats) - a 26-week series of hour-long dramas for the entire family.
PBS's first prime-time family drama series started airing on Oct. 1 with a skillfully poignant tale of the transition from slavery to freedom, as seen through the eyes of young Booker T. Washington. ''Booker'' told the story of a young black who wanted to learn to read at a time when learning to read was considered a crime for blacks in the South.
Second in the series, ''How to Be a Perfect Person in Just Three Days'' (Monday, Oct. 8, 8-9 p.m., check local listings) is a delightful hour of wacky whimsy, which somehow turns out to be also worldly and worthy. It's a fantasy based in reality - about Milo, a 12-year-old ''klutz'' who won't do anything unless he can do it perfectly and be a winner.
Starring Ilan Mitchell Smith, Wally Shawn, and Hermione Gingold, ''How to Be Perfect'' is hilarious family comedy. In the long run, Milo achieves a bold and daring victory - but somehow misses perfection. Through the mysterious ministrations of Dr. Silverfish, he learns a great truth of life: ''Perfect is never doing anything wrong, which means never doing anything at all. Perfect is boring!''
Once you've learned that lesson - and it is a lesson for the whole family - according to this delightful script, ''you can have fun - even eat things that give you bad breath.''
On Oct. 15 and 22, ''Wonderworks'' changes pace radically with a two-part drama about the harsh realities of prejudice, brutality, and the death of a loved one as seen through the eyes of a 10-year-old lad in rural Saskatchewan during the Great Depression. Jose Ferrar as ''Old Ben'' makes it all believable, with Brian Painchaud as the boy.
Prime mover behind the series is executive director Jay Rayvid, who is also executive director of the Children's and Family Consortium, which produces the series. The Consortium is made up of WQED/Pittsburgh, KCET/Los Angeles, KTCA/Minneapolis-St. Paul, WETA/ Washington, D.C., and South Carolina ETV Network.
In an interview, Mr. Rayvid proudly proclaimed the enthusiastic support of Peggy Charren of Action for Children's Television, who calls the series ''a feast for sore eyes.'' Rayvid served as executive producer for ''Once Upon a Classic,'' which ran for six years on PBS and received two Emmies as well as a Peabody Award.
''The essence of what we are trying to do,'' Rayvid says, ''is create an electronic hearth around which the whole family can gather.'' All the stories are entertaining, he emphasizes, but all contain strong moral fiber.
According to Jay Rayvid, the Monday 8 p.m. time slot was chosen because so many youngsters watch Monday Night Football later on. ''Only 8 percent watch Saturday morning television. The majority of kids watch from 8-9 p.m. every night, which may not be the best TV conceived for kids since so much is violence prone, although some is good,'' he says.
Mr. Rayvid is eager to win a big audience for ''Wonderworld'' because PBS has been ''skewing the 8-9 p.m. slot toward science recently, with shows like 'Nova' and 'Nature' and 'Smithsonian World.' There never has been drama for the family on PBS at 8 p.m.''
He insists, however, that it has to be thoroughly entertaining ''although there is a lot of educational bonding. People must watch it because it's a lot of fun to watch.''
But aren't there some fine shows on commercial TV that answer the same need - like ''Call to Glory,'' which also airs at 8 p.m. on Mondays (on ABC)?
''Well, granted 'Call to Glory' is better than most, where else is there a regular time spot in prime-time commercial television for fine shows for young people and their families? All over commercial TV there are on occasion wonderful shows that parents and their children can watch together, but is there a feeling of security that it will always be a fine, healthy experience? We want to provide a continuing space for that to happen.''
Another upcoming ''Wonderworks'' show that excites Rayvid is ''Ofoeti'' (Oct. 29) starring Susan Anton as a mermaid and Sam Waterston as a troll. In fact, most of the dramas utilize star performers who seem to be eager to appear in such highly motivated original productions. ''Ofoeti'' concerns a youngster's efforts to retain childhood dreams in a high-tech world.
ACT's president Peggy Charren calls the series ''a great dramatic banquet.'' Then she goes on to muse that ''it is sad and very wonderful that from the most underfunded segment of the medium comes a 'Wonderworks.' The Corporation for Public Broadcasting, which receives money from the government through an act of Congress, funded the series.''
Why not commercial underwriting?
Mr. Rayvid shakes his head sadly, looks upward. ''Why not? Perhaps you can tell me. Everybody recognizes the need for good family TV. And now we have a chance to have it. Yet, when we ask for a few American corporations and foundations out there to come forward to help....'' Political debates
The first of two debates between President Ronald Reagan and former Vice-President Walter Mondale, sponsored by the League of Women Voters, airs on Sunday, Oct. 7, from 9 to 10:30 p.m. Eastern time (check local listings). It will originate from the Kentucky Center for the Arts in Louisville, Ky. Barbara Walters will be the moderator, with a panel of journalists asking each candidate the same questions on economic and other domestic issues. There will be four-minute closing statements by the candidates as well.
All the networks - CBS, ABC, NBC, and CNN (cable) - plan complete coverage as well as analyses to follow. All plan to have their own anchor men live from Louisville.
On Thursday, Oct. 11, the league will sponsor a vice-presidential debate between Vice-President George Bush and Rep. Geraldine Ferraro from 9 to 10:30 p.m. It will originate from the Philadelphia Civic Center. Sander Vanocur will be the moderator, with a panel of journalists asking questions on domestic and foreign policy issues.
All networks plan complete coverage as well as analyses to follow.
On Sunday, Oct. 21, the second League of Women Voters debate between the presidential candidates will air from 8 to 9:30 p.m. Eastern time from the Municipal Auditorium in Kansas City, Mo.
Current plans are to retain the original format, although the moderator will be Edwin Newman. Discussion will concern defense and foreign policy.
A note of political sophistication: The Dallas Cowboys, New Orleans Saints, and the NFL have agreed to delay starting times of their football games until 9: 30 p.m. when the debate ends.
A note of political unsophistication (perhaps slightly influenced by commercial crassness): Networks are still undecided as to whether or not to offer post-debate analyses, which would conflict with the football kickoffs.