So you want to know about Mandolin?!?
The mandolin is an 8 stinged instrument. It is a "child" of the Lute. While the lute dates to biblical times, the mandolin came about somewhere in the 1300s. The instrument started out with a "bowl back" shape currently refered as a "tater-bug.". Its current shape was designed around the turn of the 20th century. The Gibson corporation led the way for designs and promoted its instruments to Mandolin Orchestras that were prevalent at the time. Today's favored instrument design is based on a 1923 or 1924 "Loyd Loar F-5 Model." It is primarily played in Bluegrass music, but has also found its way into many other more modern styles.