Folk-style musician John McCutcheon will be returning a favor when he performs Tuesday at Georgetown University's Gaston Hall.

When McCutcheon needed classical musicians for his latest album, his mother-in-law, Rosemary Monagan, president of the Washington Bach Consort's board of directors, suggested he work with members of the Consort. When the Consort wanted to raise money, they asked McCutcheon to give a benefit performance.

The concert opens with Washington's Reed Family Singers, five siblings, age 5 to 16, who perform gospel music. Then McCutcheon will play his wide repertoire of instruments, featuring guitar, fiddle, banjo, autoharp, Austrian jaw harp and hammered dulcimer.

McCutcheon is probably best known for his work with the hammered dulcimer, although it is the instrument he has most recently begun playing.

"It's the one I feel least constricted by. There are no rules. When I wanted to learn to play the fiddle, I watched fiddlers. When I wanted to learn the autoharp, I watched autoharp players. There were no hammered dulcimer players to watch for the first two or three years. It was a barren artistic wasteland, but I was dying to play it," he says.

McCutcheon has played everything from Bach to Latin music to rock 'n' roll on the dulcimer. "Once an instrument becomes simply a tool you have command over, it doesn't matter if it's jazz or Appalachian. If you can hear it in your mind, you can play it."