There’s some confusion about how to call the electric bass. Many people call it “bass guitar”. Let’s look at the basics: the electric bass is shaped like a guitar, has four strings and is tuned like a string bass. Nowadays there are also electric basses with five and six strings.
Until the late nineteen-sixties the electric bass was called by many “Fender bass”, because Fender was the first company to market electric basses on a large scale. During the late sixties the term “electric bass” became also common. The term “bass guitar” is a little bit confusing, because there’s also an instrument called “Danelectro bass guitar”, which is a six string guitar tuned one octave down.
In the fifties and sixties the Danelectro bass guitar was often used in combination with a string bass and was responsible for the “click” sound that you can hear on many country songs. For example on Patsy Cline’s “Crazy”. Usually the Danelectro doubled (playing unison) the string bass or the electric bass. The combination of string bass and electric bass was also popular in the sixties. A good example is “These Boots Are Made For Walkin'”. Chuck Berghofer is on string bass, Carol Kaye on electric bass.
There are at least two famous songs that use a Danelectro and on which Carol Kaye also played: on the Richie Valens hit “La Bamba” you can hear Rene Hall on the Danelectro, Carol Kaye played the rhythm guitar. On “Wichita Lineman”, Glen Campbell plays a wonderful solo on a Danelectro he borrowed from Carol Kaye, while Kaye herself played the electric bass. And you can hear Carol Kaye playing the Danelectro on “The Beat Goes On” by Sonny and Cher.