"It's something like a sex-change operation," says Tina Chancey, who has switched from one musical instrument to another. "I took violin lessons, but I was a terrible violinist. I loved stringed instruments, but not the violin family. There is something about the viola da gamba family that I am sympathetic with."

She is so smitten with the pardessus de viole, a member of the viola da gamba family, that she applied for and received a $5,000 "Solo Recitalist" grant from the National Endowment for the Arts enabling her to take her unusual instrument on tour.

And this past summer she purchased a $12,000 pardessus made in France in 1740. From a crop of almost 1,000 made by Louis Guersan, only 70 are left in the world, and Chancey has one.

Armed with a grant and an authentic pardessus, all Chancey needed was an accompanist. That was easy enough to find. She is a member of Hesperus, a Baroque ensemble in residence at Georgetown University. "I took Hesperus along as my backup group," says Chancey. "The nature of the music is that a lot of it was written for the instrument with ensemble -- mostly duet and trio. I had to take some people along to play it with me."

They have recently completed an eight-city tour and are tuning up for a concert of Baroque German Christmas music at 8 p.m. Saturday at Georgetown University's Gaston Hall. Hesperus specializes in original Baroque instruments. Most members of the audience won't need an introduction to the harpsichord or the recorder. By the end of the evening, they may consider the pardessus an old friend.