▁of ▁I ona . ▁Some ▁of ▁them ▁may ▁have ▁been ▁of ▁fun er ary ▁purpose , ▁as ▁coff in ▁l ids , ▁while ▁others ▁may ▁have ▁formed ▁part ▁of ▁a ▁larger ▁stone . ▁These ▁stones ▁are ▁usually ▁displayed ▁in ▁the ▁Gro am ▁House ▁Museum ▁of ▁Ros emark ie . ▁ ▁References ▁ ▁F ras er , ▁I ain , ▁R itch ie , ▁J . N . G ., ▁et ▁al ., ▁P ict ish ▁Symbol ▁St ones : ▁An ▁Illustr ated ▁Gazette er , ▁( Ro yal ▁Commission ▁on ▁the ▁An cient ▁and ▁Historical ▁Mon uments ▁of ▁Scotland , ▁ 1 9 9 9 ) ▁ ▁External ▁links ▁▁▁ ▁Category : Symbol s ▁on ▁P ict ish ▁stones ▁Category : P ict ish ▁stones ▁in ▁High land ▁( c oun cil ▁area ) ▁Category : Black ▁Is le ▁▁▁ ▁fr : P ier res ▁P ict es ▁de ▁Ross <0x0A> </s> ▁The ▁vi ola ▁prof onda ▁is ▁a ▁bow ed ▁string ▁instrument ▁in ▁ten or - range , ▁with ▁four ▁strings , ▁which ▁is ▁bigger ▁than ▁a ▁vi ola ▁and ▁its ▁standard ▁way ▁of ▁playing ▁is ▁rest ing ▁on ▁the ▁shoulder ▁( as ▁a ▁viol in ▁and ▁vi ola ). ▁ ▁By ▁having ▁its ▁own ▁sound ▁colour ▁and ▁by ▁filling ▁the ▁entire ▁ten or - range , ▁it ▁re forms ▁the ▁usual ▁classical ▁string ▁quart et ▁and ▁comple tes ▁the ▁idea ▁of ▁classical ▁music ▁theory ▁of ▁having ▁four ▁separate ▁voices ▁with ▁their ▁own ▁tim bre ▁each ▁( s op rano , ▁alto