How Banjos Work

by Don Kress
The banjo is based on early African and Middle Eastern instruments.

The banjo is based on early African and Middle Eastern instruments.

Jupiterimages/ Images

The banjo was initially developed in the 18th century, and has been widely adopted in folk music since that time. Available in a staggering variety of styles, the basic banjo has remained largely unchanged since it was first introduced. A string similar to a guitar string is plucked just above a tightly-stretched membrane, which reverberates to make the banjo's characteristic sound. That, of course, is only the beginning of the story.

Playing Position

A banjo is held in the same position in which a guitar is held, with the body of the instrument resting on your leg or suspended from a shoulder strap. If the musician is left-handed, they will typically pluck the strings with their left hand and will "fret" the fingerboard with the fingers of their right.

The Frets

The frets on a banjo are how different notes are sounded. The strings, when plucked, produce a low-sounding note when the strings are not held down against the frets, but will produce a high-sounding note when the strings are held down at the frets nearest to the place where the fretboard meets the body of the banjo. A banjo may have different numbers of frets depending on the type of banjo. Typically, the smaller the banjo, the higher the notes will sound, and the fewer frets it will have.

The Strings

The strings of a banjo may be strummed similarly to the way a guitar is played, but the traditional method of playing a banjo is by finger picking. This is most closely related to the way a classical guitarist plays notes. Some players use steel finger picks to produce a tinny sound, while others use a variety of cellulose or plastic picks to obtain different sounds. On a four-string banjo, the thumb and forefinger may be used alternately on the top string, while the remaining fingers are used to pluck the strings below. On a five-string banjo, the thumb picks the top string, the index finger the next string, and so on. The banjo is tuned using the tuning pegs on the banjo's headstock.

Sound Production

Sound is produced in a banjo by the reverberation of the strings passing through the membrane on the top of the banjo and causing the membrane to vibrate. If the banjo is fitted with a resonator, or a piece of solid wood fitted over the back of the banjo, the sound is amplified because the sound waves cannot pass as easily through the back of the banjo, and instead are projected back through the membrane. Without the resonator, the banjo has a slightly more quiet sound, though the tone does not change appreciably.

Photo Credits

  • Jupiterimages/ Images