The Bunkhouse Orchestra _ from the left, Leonard Coulson, Ron Kane, Hal Cannon and Tom Carter, will present the last in a series of free concerts in connection with the exhibit "Instruments of Expression: The Contemporary Luthier" at 7:30 p.m. Friday at the Art Barn. Formerly known as the Deseret String Band, the group was formed in 1972 and subsequently has performed across the United States and Europe. The name change occurred in 1985, the result of a shift of focus to rural music of the 19th century American West. The group plays cowboy music employing, variously, fiddle, banjo, guitar, mandolin, harmonica and pitched fork. Both the concert and the exhibit are sponsored by the Salt Lake City Arts Council.