After a week of discussion, Sarah Caldwell's Opera of Boston and the D.C. Federation of Musicians have resolved their differences in a conflict that centered upon which orchestra the company would use when it opens at Wolf Trap next Thursday. Caldwell wanted to bring her entire orchestra from Boston and the union wanted musicians from the D.C. area to be employed.

Under the resolution agreed to late Wednesday afternoon, Caldwell will be able to bring from Boston the 15 first-chair players of her company's orchestra. The rest of the musicians will be recruited locally.

"Both sides feel miserable, which means it is a good resolution," said Sam Jack Kaufman, president of the D.C. Federation of Musicians.

According to Craig Hankenson, Wolf Trap's executive director, 40 extra hours of rehearsal time with the orchestra will be necessary, adding $25,000 in production costs for the three operas to be performed. No rehearsals had been scheduled at Wolf Trap when it was anticipated that the Boston company would bring its own orchestra. Hankenson said the additional expenses would be shared by Wolf Trap and the Opera Company of Boston.

Asked about the resolution, Caldwell said, "I'm disappointed that the union did not see fit to accept our invitation to bring Washington players to Boston in exchange for bringing Boston players to Washington." (During the discussion the Boston muscians' had agreed to such an offer.) "This open exchange could make possible many wonderful things. I hope that the question can be reconsidered in the future."

Caldwell, who opens the National Symphony Wolf Trap concerts tomorrow evening, said: "I look forward to an exciting season and a very fine opera week. I'll try to do my best and I'm sure the musicians will do their very best."