The 4-string banjo (also known as "Samba-banjo" or banjo-cavaco) is a Brazilian instrument which is derived from the cavaco, and is especially associated with Samba and its variants. The 4-string banjo was first introduced by musician Almir Guineto in the late 1970s and early 1980s, attending on one hand the necessity for a louder instrument similar to the cavaco, and on the other, the drive for innovation.
The samba banjo has the same tuning and range as the cavaquinho, but its timbre is quite different, sounding like a traditional banjo but pitched higher. It is played with a pick for rhythm accompaniment, with sophisticated strumming beats; thus it is a primarily a rhythmic instrument, and virtuosity is sometimes considered to be based on breaking repetitive patterns and surprising the listener with unexpected and inventive rhythmic figures, while keeping the rhythm steady.