as droning, shuffling, and ornamentation specific to particular styles are used. In many traditions of folk music, the tunes are not written but are memorized by successive generations of musicians and passed on in what is known as the oral tradition. Many old-time pieces call for cross-tuning, or using tunings other than standard GDAE. Some players of American styles of folk fiddling (such as bluegrass or old-time) have their bridge's top edge cut to a slightly flatter curve, making techniques such as a "double shuffle" less taxing on the bow arm, as it reduces the range of motion needed for alternating between double stops on different string pairs. Fiddlers who use solid steel core strings may prefer to use a tailpiece with fine tuners on all four strings, instead of the single fine tuner on the E string used by many classical players. Arabic music As well as the Arabic rababah, the violin has been used in Arabic music. Electric violins Electric violins have a magnetic or piezoelectric pickup that converts string vibration to an electric signal. A patch cable or wireless transmitter sends the signal to an amplifier of a PA system. Electric violins are usually constructed as such, but a pickup can be added to a conventional acoustic violin. An electric violin with a resonating body that produces listening-level sound independently of the electric elements can be called an electro-acoustic violin. To be effective as an acoustic violin, electro-acoustic violins retain much of the resonating body of the violin, and often resemble an acoustic violin or fiddle. The body may be finished in bright colors and made from alternative materials to wood. These violins may need to be hooked up to an instrument amplifier or PA system. Some types come with a silent option that allows the player to use headphones that are hooked up to the violin. The first specially built electric violins date back to 1928 and were made by Victor Pfeil, Oskar Vierling, George Eisenberg, Benjamin Miessner, George Beauchamp, Hugo Benioff and Fredray Kislingbury. These violins can be plugged into effect units, just like an electric guitar, including distortion, wah-wah pedal and reverb. Since electric violins do not rely on string tension and resonance to amplify their sound they can have more strings. For example, five-stringed electric violins are available from several manufacturers, and a seven string electric violin (with three lower strings encompassing the