The banjo is a stringed musical instrument whose characteristic round body is actually a drum head. That structure is what produces the loud and distinctively bright and happy sound for which the banjo is known. Multi-talented actor Steve Martin, who plays the banjo in various styles, showed that it is actually hard to play a sad song on a banjo in one of his early Saturday Night Live appearances, though Tom Dooley as done by the Kingston Trio is a good counter-example. Charles Schultz, creator of the Peanuts comic strip, once said, "Every child born should be issued a banjo."
Anatomy of a Modern Banjo
The three basic parts of a banjo are the body, the neck, and the peghead. The peghead is a flat piece of wood to which the tuning pegs are attached. Modern banjos use geared tuning machines like those used on guitars rather than simple friction pegs like those used on violins.
The peghead is attached to the top end of the banjo neck, which is the long, narrow wooden piece that connects the peghead to the body. The top surface of the neck is covered with a fingerboard that is made of a rather thin sheet of wood, usually ebony, rosewood or other fine hardwood. The fingerboard is most often fretted. A few banjos feature a removable insert for the top four frets that allow the banjoist to switch between fretted or unfretted fingering for that area. The strings are stretched over the fingerboard, supported at the top by the nut, which is a thin strip of bone or plastic that serves an an upper bridge and is notched to hold the strings in position.
The bottom end of the neck is attached to the body of the banjo. The body is a rather complex assembly of parts that are collectively referred to as the pot. The pot comprises the head, the tension hoop, the tone ring, the rim, a set of hooks and nuts, a shoe or flange, either a dowel stick or one or two coordinator rods, the armrest, the tailpiece, the bridge, and possibly a removable resonator.
The banjo head is a thin, flexible covering that corresponds to a drum head. Nearly all modern banjos use mylar plastic heads, but calfskin vellum is still sometimes used. The tone ring is a cast metal ring that supports the head. Some banjos do not have a tone ring, and the head is supported directly by the rim. The head is stretched over the tone ring and clamped in place by the tension ring, which is usually a thin band of metal. The tone ring rests on the rim, which is a short cylinder made of wood or metal. The shoe or the flange is a metal piece that is attached to the bottom of the rim to provide a place to attach the hooks. The hooks are the short rods that you see arranged around the body of the banjo. The hooked end fits on the tension hoop and the threaded end is attached to the shoes or the flange by nuts. The hooks pull down on the tension hoop to make the head taut and to hold the pot together. The dowel stick (or coordination bar) fits inside the rim and extends from the place where the neck is attached to the opposite side of the rim where the tailpiece is attached. It supports the pot against the tension of the strings. The tailpiece holds the bottom ends of the strings.
The bridge is thin piece of wood or other material that rests on the banjo head and holds the strings in position at the proper distance above the head and fingerboard. The bridge transfers the vibrations of the strings to the head. The bridge and the nut (upper bridge) together determine the effective length of the strings. The armrest is a small platform that attaches to the side of the pot. It helps position and steady the right hand for picking. The resonator is a thin wooden bowl that serves as a supplementary sound box to amplify the banjo sound and produce a richer tone. It attaches to the flange at the bottom of the pot.
Types of Banjos and their Playing Styles
There are several variations on the construction of a modern banjo, each of which is suited to particular playing styles and types types of music. The three most common types that are played today are the 5-string banjo (especially its variant, the bluegrass banjo), the tenor banjo and the plectrum banjo. Other types include the banjulele, the zither banjo and the various classical banjos. There are versions that have six and even seven strings.
The 5-string bluegrass banjo is probably what comes to mind when most North Americans think of a banjo. The fingerboard of the bluegrass banjo has 17 or 19 frets (sometimes 20). The strings are metal. Four of the strings run the full length of the neck and are tuned to an open major chord, most often G major. Strumming the four open strings produces the G major chord. The fifth string is an open drone string tuned to G, but one octave above the other G string. The tuning is thus written gDGBD, with the small g indicating the higher tuning of the fifth string. Being a drone string, the fifth string is usually not fretted. It is shorter than the others, nutted at the fifth fret. It is the string closest to the player and is played with the thumb. The bluegrass banjo can be played with either the three-finger picking style or the clawhammer style. The tone ring is generally made of cast metal and is heavier than the tone rings of other types of banjo. The tone ring is so designed to make the banjo sound louder and to produce the characteristically bright, sparkling sound favored in bluegrass music. Another distinguishing feature of bluegrass banjo is the resonator, which is needed for the voice of the banjo to be heard in a bluegrass band. This is particularly important because in bluegrass, the banjo usually plays a solo lead during a tune, or it may be the primary lead instrument.
The tenor banjo has four strings, which are usually tuned to CGDA. It has either 17 or 19 frets on the fingerboard. This banjo is strummed or picked with a flat pick for rhythmic accompaniment in Dixieland Jazz, jazz and some Celtic music.
The plectrum banjo has four strings, which are usually tuned to CGBD (or GDAE for Celtic music). It has 22 frets, which give more latitude in fingering melodies, making it more suitable than the tenor banjo for solo melodic playing. It is played with a flat pick (plectrum). In practice, there is a lot of overlap in the way the tenor and plectrum banjos can be played.
The history of the banjo is a significant thread woven into the fabric of American history, extending from the early days of slavery up through the important social movements of the twentieth century in the United States.