| A regular double bass. | An electric double bass. |
The double bass is an Earth musical instrument and the largest member of the violin family.
A variation of the instrument is the electric double bass which doesn't need a resonating body. These instruments were often seen in the 24th century.
One crewmember of the USS Enterprise-D played an electric double bass during a concert in Ten Forward that Commander William T. Riker also participated in. (TNG: "Second Chances")
During the wedding of Commander Riker and Deanna Troi in 2379, an electric double bass was part of the small orchestra that played at the wedding reception. (Star Trek: Nemesis)