The double bass, also called bass viol or contrabass, is the largest and lowest-pitched member of orchestral stringed instruments. The standard double bass has four strings and a range from E an Octave below the bass staff, upwards for nearly three octaves, some instruments may have five strings in order to extend the range downward. Some early double basses had only three strings. The instrument is played with a heavy bow and sounds an octave lower than is written notes. Its body shape differ from the other members of the violin family in having sloping rather than rounded shoulders and usually having a flat rather than a convex back.
The double bass, the lowest pitch members of the violin family, probably developed from the double bass viol. The double bass stands 1.8 m (6 ft) tall and has four strings tuned in fifths. It is played standing.