The double bass, or upright bass is the largest and lowest-pitched bowed string instrument of the viol family in the modern symphony orchestra.

The double bass is a standard member of the string section of the orchestra[1] and smaller string ensembles in Western classical music. The double bass is played either with a bow (arco) or by plucking the strings (pizzicato). In orchestral repertoire and tango music, both arco and pizzicato are employed. In jazz, blues, and rockabilly, pizzicato is the norm. While classical music uses just the natural sound produced acoustically by the instrument, in jazz, blues, and related genres, the bass is typically amplified with a bass amplifier.