The D.C. Youth Orchestra traveled to Switzerland in 1970, Germany in 1972 and Scotland in 1974, and with some luck, hard work and money, it will go to Tokyo in 1978.

Lyn McLain, director and co-founder of the orchestra, has just accepted an invitation for the orchestra to participate in workshops and performances at Japan's National Music Camp in August, along with youth orchestras from Tokyo, Kyoto and Kumamoto.

McLain hopes to arrange performances in other Japanese cities in return for meals and lodging for the students and staff. The three-week trip to Tokyo would be the fourth international trip for the youth orchestra since its founding in 1961.

When McLain announced the trip at a rehearsal last week, he was greeted with broad smiles. When he said he would try to arrange a performance in Hawaii on the way, the students cheered.

Orchestra member Eric Samuda, a violinist and senior at McKinley High School, tried to contain his excitement.

"I ssure hope I can go," he said. "But I've applied to the U.S. Air Force Academy, and if I'm accepted, I'll have to start classes over the summer."

McLain, too, is trying to keep his enthusiasm under wraps. Before even planning the trip, the D.C. Youth Orchestra program must raise about $80,000 to keep its six-week summer school in operation, he said.

The program offers students 20 hours of instruction a week, free of charge, at Coolidge High School at 5th and Tuckerman Sts. NW. Fund raising is particular importance this year because of a reduction in arts instruction funding by the D.C. public school system.

The conductor of the Tokyo Junior Philharmonic, Setsuo Tsukahara, has promised to arrange free meals and lodging for members if the youth orchestras gets to Japan.

Plane fare must be raised, however, for the 107 young orchestra members and for about 20 other persons, including orchestra staff members, parent chaperones, a doctor, nurse, lawyer and interpreter. Dr. Robert Maroney, president of Friends of the D.C. Youth Orchestra Inc., estimated the cost of the plane fares at $150,000.

The fund raising strategy for the trip has not been worked out, but Maroney said he hopes to reduce the transportation cost to students as much as possible. Parents will be asked to contribute as much as they are able, he said.

Plans for the Tokyo trip have been brewing since the summer of 1974, when McLain met Tsukahara at an international youth orchestra festival in Aberdeen, Scotland. Last year, the Tokyo Junior Philharmonic Orchestra came to Washington, where it gave joint performances with D.C. Youth Orchestra at the White House and the Kennedy Center.

"Last year, the Japanese students stayed in orchestra members' homes, which ranged from mansions in Bethesda to rowhouses downtown," said McLain. "I want the kid to have the same kind of experience when we go to Japan."

Eric Samuda said that if he were able to go on the trip, he would buy a Japanese-English dictionary first thing.

"I only know two Japanese words - 'ohyo' (good morning) and 'sayonara,'" he said.

"Last year, it was hard to communicate with the Japanese students, because we didn't know any Japanese and they only spoke a few phrases of English. But we could still relate to each other. As they say, music is the universal language," Eric said.

For Allen Chan, a senior at Woodrow Wilson High School and a trumpet player in the orchestra, musical communication was the most impressive aspect of the youth orchestra trip to Scotland in 1974.

"There were orchestra there from all over the world and concerts almost every night. Everyone in the audience was a musician, so everyone understood each other without speaking at all," Allen explained.

Other orchestra members have never been abroad, like Lillian Loman, a violinist and senior at McKinley High School. She began learning violin at the age of 6 from her aunt, a public school teacher, and joined the Youth Orchestra three summers ago. Her younger sister and brother take classes in the D.C. Youth Orchestra program.

This winter, the program is offering classes to 868 students and has a staff of 70 professional musicians. Traditionally, students like the Lomans work their way up through a series of classes, ranging from beginning to advanced, until they are skilled enough to audition for the orchestra.

The program is administered by Friends of the D.C. Youth Orchestra, a board of parents and advisers, and is funded by the D.C. public school system, foundation and federal grants and private contributions.

Students may devote from four to 15 hours a week to the orchestra, for classes, rehearsals and performances. McLain warned that a trip to Tokyo would mean that the students would have to give more performances during the summer to raise money and practice more to clean up "raggedy edges."

Being in the orchestra already means giving up some TV and staying up late to study, said Lillian Loman.

"It's a hassle doing your homework after Thursday night rehearsals, especially when there are tests on Friday," she said. "But it pays off during performances, especially when you get ovations."

And a trip abroad is a special bonus. Says the orchestra's concert mistress Sally Stout, "Going to Scotland was the best thing I've ever done with the orchestra."