The ancestry of the
double bass has its roots in both the viol and the violin families of
stringed instruments. In the modern orchestra, the double bass (aka
doublebass or contrabass) is generally tuned in fourths - like the viol
family instruments. Among the viol family instruments, modern audiences
are perhaps most familiar with the viol da gamba - which displays a body
shape with corners that do not turn out - that is characteristic of this
Today, however, the double bass is also considered to be a member of the violin family of instruments. It is played as the largest string instrument in the modern orchestra and in classical period music it normally doubles the bass line an octave lower. The 'cello, (violoncello) is the original bass (think of the famous "Bass of Spain" 'cello by Stradivari) because it plays the bass clef line in the orchestra. The double bass is really a transposing instrument, playing notes which sound an octave lower than the ones written in the bass clef.
In the photo below, Jim is holding his gamba model on the right ("gamba corners" that don't turn out) and his violin model on the left (out-turned corners like a violin). For more information on each model and the other special features that they incorporate, please click on the links at the top of this page.