Chordophones
These instruments fit into the chordophone category in the Hornbostel-Sachs Classification System. This means that one or more strings are stretched and vibrate to produce the sound. 
Cello

This instrument is 4 feet tall and 1'4" wide.  It has 4 strings and can be played with a bow similar to the bow pictured with the violin or the strings can be plucked with the fingers.  It is held in a seated position between the player's knees.  An endpin extends from the bottom of the body and rests on the ground to raise the instrument into playing position.

The classification number is 321.322
Guitar

This instrument is 3'4" tall by 1'2" wide.  It has 6 strings.  It can be played in a seated or a standing position.  The strings can be plucked with the fingers of the right hand or with a plectrum.  The neck extends to the left side of the player.

Guitars are gaining in popularity in Papua New Guinea.  They are used by popular musicians and in some churches.

The classification number is 321.322
Violin

This instrument is 2 feet tall and 8 inches wide.  It has 4 strings.  The strings can be  played with a bow or plucked with the fingers of the right hand.  Playing position is seated or standing with the instrument perched on the left shoulder.

The classification number is 321.322