A bass banjo is a special type of banjo that is normally larger and tuned lower than traditional versions. This instrument was first developed to play the low parts in banjo orchestras. There are several types of these instruments, and they vary based on the number of strings, four or five, and position when playing. Some types stand on the ground like a cello, while others are held at an angle across the body, like a bass guitar.
Built in a fashion similar to traditional banjos, the bass banjo consists of an animal hide or plastic material that has been stretched over a circular frame. The back may be covered, known as a resonator, or be open. This style of banjo may have four or five strings; the player will pluck the strings, which cause the animal hide or plastic to vibrate, producing sound.
The first instrument to be considered a bass banjo was the five-string cello banjo. This string instrument played a full octave lover than the traditional versions. Unlike regular banjos, the five-string cello type is played in a manner similar to an upright bass; the instrument rests on the ground, leaning on an end pin. This deeper sounding banjo was developed due to the growth of banjo orchestras, which became popular during the later 1800s. These orchestras needed banjos that could produce sound at different ranges, and the bass version was used to play all the lower orchestra parts.
As mandolin, or four-string guitar, orchestras became more popular at the beginning of the 1900s, a four-string bass banjo was created. This version was played in the same way as a bass guitar; it did not rest on the floor but was held at an angle across the body. The tuning of the four-string instrument was similar to a cello, with the strings tuning on C, G, D and A notes. A modified four-string version was also made in a style similar to that of an upright bass.
Historically, there were many different manufacturers of these instruments. S.S. Stewart made the first version in 1889, and Gibson began producing a four-string version in 1919 called the CB-4. Besides musician-made instruments, as of 2011, the only manufacturer of the bass banjo is Gold Tone.