Bass guitar in 1958. 1956 saw the appearance at the German trade fair "Musikmesse Frankfurt" of the distinctive Höfner 500/1 violin bass made using violin construction techniques by Walter Höfner, a second generation violin luthier. The instrument is often known as the "Beatle Bass", due to its endorsement and use by Beatles bassist Paul McCartney. In 1957 Rickenbacker introduced the model 4000 bass, the first bass to feature a neck-through-body design in which the neck is part of the body wood. The Fender and Gibson versions used bolt-on and glued-on necks. With the explosion of the popularity of rock music in the
Bass guitar neck construction. While neck-through construction is most common in handmade "boutique" basses, some models of mass-produced basses such as Ibanez's BTB series also have neck-through construction. Bolt-on neck construction does not necessarily imply a cheaply made instrument; virtually all traditional Fender designs still use bolt-on necks, including its high-end instruments costing thousands of dollars, and many boutique luthiers such as Sadowsky build bolt-on basses as well as neck-through instruments. The number of frets installed on a bass guitar neck may vary. The original Fender basses had 20 frets, and most bass guitars have between 20 and 24 frets or fret