Normally one finds two variations in the original form of the mandolin – the acoustic and the electric (solid block).
The mandolin in its original form is typically an acoustic stringed instrument about 60cm (2 ft) long with deeply vaulted ribs and a table slanted downward at the lower end. It has a neck-cum-peghead attached to a hollow oval shaped sound box. It has four pairs of loop-ended double rib fastened metal strings secured to hooks on the body on one end, and passed across a low bridge (on the sound box) and a nut (on the finger board) to the pegs inserted into a rectangular peg-box. A small flexible plectrum is used to vibrate the strings. A feature of mandolin playing is the constant reiteration of all long pitches, which counteracts its weak sustaining power.