Electric mandolin 4-string version. A related instrument, the Bahian guitar, was developed in Brazil beginning in the 1940s. Bahian guitars typically have a solid body and 4 or 5 single-course strings tuned in fifths, but are considered to be electric versions of the cavaquinho rather than the mandolin. Both four string single course and eight string double course solid body mandolins have been produced by several makers, as well as five string single course models. From 1956 to 1976, Fender produced a four string version which they simply called the "Fender Electric Mandolin". Its body shape was based on a smaller version
Octave mandolin also varies widely, from as few as 17 to as many as 24 frets: 18 or 19 frets is typical. From the mid-20th century on, a number of makers have produced octave mandolins with guitar-shaped (e.g., the "hourglass" or "figure-8") bodies. These instruments are typically constructed essentially like acoustic guitars, with similar woods and internal bracing. the neck, however, is much narrower, and supports the mandolin string layout, rather than the traditional 6-strings of the guitar. As with the mandolin and mandola, the octave mandolin has four courses of two strings each. The two strings in each course are tuned