The term 'four-stringed guitar' refers to two different instruments: the ukulele and the BASS. The ukulele is a small, four-stringed instrument that originated in Hawaii and is typically associated with Hawaiian music. It is also popular in other genres such as jazz and pop. The BASS is a larger, four-stringed instrument that is commonly used in rock, jazz, and other genres of music. It is usually played with a pick or fingers and is used to provide the low end of the musical spectrum. Both instruments are essential components of any band or ensemble.