There are styles of the mandolin.
Mandolin . It commonly has four courses of doubled metal strings tuned in unison ( 8 strings ) , although five ( 10 strings ) and six ( 12 strings ) course versions also exist . There are many styles of mandolin , but three are common , the Neapolitan or round-backed mandolin , the carved-top mandolin and the flat-backed mandolin . Each style of instrument has its own sound quality and is associated with particular forms of music .