The Banjo was first played in Africa. Actually, its earliest version, called a "banjar", was fashioned from a gourd, using an animal skin for the drum head and gut strings which were stretched up the neck of the gourd. The African slaves are credited with introducing the banjo into the United States, and over the last 100 years it has become one of the most popular of all folk instruments.
On the 5-string banjo, two major styles of playing have developed, including the old-time, "clawhammer", style which evolved in the Appalachian mountain region from African influences, and the "Bluegrass" style which involves the fast three-finger picking popularized by Earl Scruggs. The 4-string or "tenor" banjo is used primarily in "dixieland" jazz music. The banjo is not difficult to play, and with a good teacher, it's great fun learning how.
Timmy plays an open back banjo which was custom made for him by the Deering Banjo Company in Lemon Grove, California. The banjo has a Grenadilla wooden tone-ring and an extra-deep pot, which gives a more sustained ring (great for song accompaniment).
By the way, Deering makes an excellent beginner banjo called "The Goodtime Banjo", which is a gem of an instrument, and is recommended to anyone interested in having a high quality yet inexpensive banjo. Visit their website at www.deeringbanjos.com.