James Oliver Bolyard, 52, a professional musicologist and leading exponent of the baroque bassoon, died of liver cancer June 4 at Virginia Hospital Center-Arlington. He was a resident of Arlington County.

Mr. Bolyard, a bassoonist for a number of musical ensembles, was equally facile in the baroque and modern bassoons. He did extensive research in exotic repertoire for the instrument and was a prolific transcriber of solo and ensemble pieces.

In a 1997 Washington Post article, writer Joe Banno reviewed the Washington Bach Consort's closing performance of its "Rush Hour" concerts that featured a set of baroque trio sonatas on original instruments. Mr. Bolyard was among the four musicians performing at St. John's Church.

"James Bolyard had the toughest assignment, wresting smooth sound from a recalcitrant period bassoon that tended to stray from pitch when pushed above mezzo-forte. But he exploited its quaint, saxophone-like timbre in the Handelian Bassoon Sonata No. 5 by J.E. Galliard, and made something suave out of the energetic bustle in Telemann's Trio No. 6 for Violin, Bassoon and Continuo," Banno wrote.

Mr. Bolyard was born in Puerto Rico, where his father was stationed with the Navy, and grew up in Coral Gables, Fla. He received his bachelor's degree from Peabody Institute in Baltimore and did graduate studies there also.

He was editor and publisher of Whisper Key Press, a one-man music publishing company specializing in 17th- and 18th-century bassoon repertoire. He started the company in the early 1990s and operated it until the time of his death.

Mr. Bolyard was principal bassoonist for ensembles including the Washington Chamber Symphony, the Washington Bach Consort, the Wolf Trap orchestra, the Violins of Lafayette, the National Gallery Orchestra and the National Theatre. He was a member of the Smithsonian orchestra, the Rosewood Quintet, the Dryden Ensemble in Princeton, N.J., Publick Musick in Rochester, N.Y., and the Boston Bach in Boston.

During his career, he performed with the Richmond, Baltimore and National symphony orchestras. He also performed frequently with the Theater Chamber Players, Washington National Opera, 20th Century Consort, Library of Congress Ensemble, Choral Arts Society of Washington, Master Chorale, Washington Chorus and Cathedral Choral Society.

His baroque engagements included the Folger Consort and Hesperus and Aradia in Toronto. He also performed at the 92nd Street Y in New York with Il Gardellino and Oslo Baroque Soloists.

Mr. Bolyard also taught bassoon performance at the Baroque Performance Institute at Oberlin College, Towson University, James Madison University and the Levine School of Music.

His discography includes works of Christoph Willibald Gluck, George Frideric Handel, Carl Philipp Emanuel Bach, Jean-Philippe Rameau and Johann Sebastian Bach.

There are no immediate survivors.

James Oliver Bolyard performed with the Richmond, Baltimore and National symphony orchestras, among others.