When Carlton King's eyes alighted upon a book of alchemy published around 1600 A.D., its three-word title, "A Newe Jewell," stood out.

The Laurel musician had found a name for his trio, which specializes in Renaissance chamber music and is one of the few American ensembles dedicated to historically accurate performances with medieval and Renaissance instruments.

Members of A Newe Jewell also lecture and conduct workshops on Renaissance instruments and music, and give private lessons in performing the music of the period and in early vocal techniques. Experimentation, thorough research and spontaneous improvisation also characterize the group.

When Pope John Paul II visited the Washington metropolitan area in 1979, A Newe Jewell presented a program of Renaissance Polish music in his honor at Georgetown University, where the ensemble is in residence each spring to perform and conduct workshops.

Alice Kosloski, of Washington Grove, is the trio's new contralto. She has been involved in early music for almost l5 years. "It's the kind of music I do best. The way the music should go, it doesn't require a big operatic voice. You just adjust to a different style," she says.

Howard Bass, lutist from Berryville, Va., says he came to that instrument through "a natural progression from classical guitar studies l2 years ago. The lute repertoire is more genuine and more available than that for guitarists."

King, managing director of the ensemble, says he prefers Renaissance music "because you can be a scholar, researcher and performer at the same time. Playing it, you have more freedom to personalize the music but you have many creative musical decisions -- how you orchestrate, to percuss or not, ornamentation, tempi -- none of which is marked in the score."

Among the copied instruments he plays are krummhorns, recorders, and a medieval hurdy-gurdy that is still popular in European folk music.

King says public attention and support for authentic, pre-Baroque music is much stronger in Europe than in the United States, but American interest is growing.

"Renaissance music must be taken more seriously as real chamber music. It has taken a long time for professional-level performances to develop. Part of the blame can be placed on a public (misconception that) the music derives strictly from the amateur madrigal group tradition in high schools and colleges," King explained.

He said most of the better pre-Baroque ensembles in America are based in Boston or New York City, and their recordings are too few to meet a growing demand.

"Audiences should not need any preparation for early music, if we are doing our job right," King continued. "We perform best before an audience of 500 or less. Playing outdoors doesn't work well, because weather affects the tuning on the instruments so much that we have to stop after every selection and tune each instrument," he adds.

A Newe Jewell belongs to the Mid-Atlantic Regional Performing Arts Touring Program Consortium, which subsidizes its concerts on tour at colleges and other small halls because of the selective audience. The subsidies do not apply to performances in an ensemble's home state, "But we are eager to perform anywhere in Maryland on any date," King added.

A concert tentatively planned for this season, "Musical Piracy in the Renaissance," has as its theme the widespread practice of borrowing musical material from other composers. The trio also plans a concert tour of Pennsylvania in October.