The four-string mountain dulcimer sounds like an angel plucking a harp. Gentle, soothing, innocent notes strung together in a lullaby.

But sometimes that angel's got rhythm. Since the mountain dulcimer was invented in the Appalachians nearly 200 years ago, it's been a natural and major component in bluegrass -- as the soprano complement to the fiddle's tenor.

"It can make you dance and it can make you real peaceful," says dulcimer champion David Schnaufer. "The name means 'sweet sound,' and it's aptly titled."

The American mountain dulcimer is thought to be a combination of the German zither and the Scottish and Irish fiddles. It was probably invented in the late 1700s in West Virginia or Virginia, along the wagon roads.

"I think the earliest one is dated about 1811," says Schnaufer, "but I just found a woman in West Virginia who has a collection of old instruments that are much older than that."

Schnaufer likes to travel around the country hunting down old mountain dulcimers. At one point, he says, he knew just about all the mountain dulcimer players. "I located them, called them up and went and played with them," he says. "But now there are so many dulcimer players. It's become a very popular instrument."

One reason is its sound. Another is because it's relatively easy to play. And it adapts to all kinds of music, from classical to Appalachian, says Schnaufer.

Schnaufer became charmed with the instrument about 20 years ago while attending college in Texas. "I saw one in a window in Austin," he says. "In fact, there were 30 of them. Someone tore down an old hotel and this man used the wood to make dulcimers and sold them for $30 apiece. I had never played one before, but I walked in and picked a few notes and said, 'That's it.' Stopped my college education and learned to play."

Recently he's toured as the opening act for the Everly Brothers, played with Emmylou Harris on a new Hank Williams Jr. album and even recorded his own, "Dulcimer Player Deluxe" (SFL).

David Schnaufer is performing at the Silver Spring Unitarian Universalist Church tomorrow night at 8. Tickets are $8 and available at the door. For information call 301-270-0222.