class ical ▁music , ▁with ▁vocal ▁range ▁that ▁typically ▁lies ▁between ▁the ▁A ▁below ▁" middle ▁C " ▁( C 4 ) ▁to ▁the ▁A ▁two ▁oct aves ▁above ▁( i . e . ▁A 3 – A 5 ). ▁In ▁the ▁lower ▁and ▁upper ▁extrem es , ▁some ▁mez zo - s op ran os ▁may ▁extend ▁down ▁to ▁the ▁F ▁below ▁middle ▁C ▁( F 3 ) ▁and ▁as ▁high ▁as ▁" high ▁C " ▁( C 6 ). ▁The ▁mez zo - s op rano ▁voice ▁( un like ▁the ▁sop rano ▁voice ) ▁is ▁strong ▁in ▁the ▁middle ▁register ▁and ▁we aker ▁in ▁the ▁head ▁register , ▁resulting ▁in ▁a ▁deeper ▁tone ▁than ▁the ▁sop rano ▁voice . ▁ ▁The ▁term ▁mez zo - s op rano ▁was ▁developed ▁in ▁relation ▁to ▁classical ▁and ▁oper atic ▁voices , ▁where ▁the ▁classification ▁is ▁based ▁not ▁merely ▁on ▁the ▁singer ' s ▁vocal ▁range ▁but ▁also ▁on ▁the ▁t ess it ura ▁and ▁tim bre ▁of ▁the ▁voice . ▁For ▁classical ▁and ▁oper atic ▁sing ers , ▁their ▁voice ▁type ▁determ ines ▁the ▁roles ▁they ▁will ▁sing ▁and ▁is ▁a ▁primary ▁method ▁of ▁categor ization . ▁In ▁non - class ical ▁music , ▁sing ers ▁are ▁primarily ▁defined ▁by ▁their ▁genre ▁and ▁their ▁gender ▁not ▁their ▁vocal ▁range . ▁When ▁the ▁terms ▁sop rano , ▁mez zo - s op rano , ▁contr al to , ▁ten or , ▁bar it one , ▁and ▁bass ▁are ▁used ▁as ▁descript ors ▁of