Eight centuries ago, troubadours traveled from chateau to chateau in medieval southern France, entertaining courtly audiences with musical poetry.

Friday at 8 p.m., the Bradley Hills Presbyterian Church in Bethesda will host a modern-day troubadour--Elizabeth Aubrey of Silver Spring. In a recital of songs and biographical anecdotes about troubadours, Aubrey will delve into that ancient realm of music and poetry.

A soprano, Aubrey will accompany herself on an Irish harp and a medieval lute, two instruments built especially for her. Lutemaker Derwood Crocker of Aurora, N.Y., copied her instrument from a picture in a 13th century Spanish manuscript. Dave Brown of Baltimore reconstructed Aubrey's harp, modeling it after an early model housed at the Trinity College library in Ireland.

"Although the width and length of the harp need to be the same size, there is no standard for medieval instruments," says Aubrey, who has learned to read early music and transcribe it into modern notation.

Aubrey's study of medieval manuscripts--she is working on a PhD in musicology--has taken her to the Bibliotheque Nationale in Paris, which houses the world's largest collection of original troubadour literature. "How the French national library would obtain the ancient manuscripts is a mystery. Most are nameless with only a shelf number," she says.

Aubrey attempts to document their origins and dates, and deciphers the dialects of their scribes. She has found only one chapter in all the manuscripts devoted to describing the style of troubadour songs, one dating to the 13th century.

In her PhD dissertation, Aubrey has corrected some misconceptions about troubadours that music historians and literary critics have generated over the years.

One discovery she has made is that medieval musicians never used fingers to pluck instruments but always a plectrum, the equivalent of the modern-day pick. The lute has 10 strings. Accompaniment and melody can be played at the same time on her harp, whose strings are arranged differently from those of modern-day harps.

In singing the early music, Aubrey has discovered that her voice is suited to troubadour music. "My type of voice is not big and operatic," she says. "These songs are simpler and more dependent on language to convey their meaning. The texts of troubadour songs are diverse. There are songs of love, satire and politics."

As a musicologist and performer, she is one of the very few who can imitate the singing style of the jongleurs, who were entertainers of the lowest status, usually lacking the poetic and compositional talents of the troubadours. The troubadours used their own musical language, called langue d'oc. Aubrey can understand the language, and speaks five or six other languages as well.

She has been performing early music for a dozen years, the harp three years and the lute for two years. Her interest in medieval music was triggered during her college days when a visiting professor lectured on and demonstrated old musical instruments.

"But I can't yet make a living as a musician," she says. For 2 1/2 years Aubrey was a member of A Newe Jewell, an early music ensemble. She now teaches a baroque music course in Georgetown University's continuing education program and has taught medieval and Renaissance music courses. The 31-year-old early music scholar says she hopes someday to teach music history full time at a university while continuing to perform as a troubadour.

"Medieval music deserves equal billing with the more popular periods such as baroque because it's still a growing field," she says.