f-holes rather than a single round sound hole. It is most commonly used by swing and jazz players and often incorporates an electric pickup. The Selmer-Maccaferri guitar is usually played by those who follow the style of Django Reinhardt. It is an unusual-looking instrument, distinguished by a fairly large body with squarish bouts, and either a D-shaped or longitudinal oval soundhole. The strings are gathered at the tail like an archtop guitar, but the top is flatter. It also has a wide fingerboard and slotted head like a nylon-string guitar. The loud volume and penetrating tone make it suitable for single-note soloing, and it is frequently employed as a lead instrument in gypsy swing. The resonator guitar, also called the Dobro after its most prominent manufacturer, amplifies its sound through one or more metal cone-shaped resonators. It was designed to overcome the problem of conventional acoustic guitars being overwhelmed by horns and percussion instruments in dance orchestras. It became prized for its distinctive sound, however, and gained a place in several musical styles (most notably blues and bluegrass), and retains a niche well after the proliferation of electric amplification. The 12-string guitar replaces each string with a course of two strings. The lower pairs are tuned an octave apart. Its unique sound was made famous by artists such as Lead Belly, Pete Seeger and Leo Kottke. Tonewoods Traditionally, steel-string guitars have been made of a combination of various tonewoods, or woods considered to have pleasing resonant qualities when used in instrument-making. Note that the term is ill-defined - the wood species that are considered tonewoods have evolved throughout history. Foremost for making steel-string guitar tops are Sitka spruce, the most common, and Alpine and Adirondack spruce. The back and sides of a particular guitar are typically made of the same wood; Brazilian rosewood, East Indian rosewood, and Honduras mahogany are traditional choices, however, maple has been prized for the figuring that can be seen when it is cut in a certain way (such as flame and quilt patterns). A common non-traditional wood gaining popularity is sapele, which is tonally similar to mahogany but slightly lighter in color and possessing a deep grain structure that is visually appealing. Due to decreasing availability and rising prices of premium-quality traditional tonewoods, many manufacturers have begun experimenting with alternative species of woods or more commonly available variations on the standard species. For example, some