▁the ▁ch ord ▁is ▁rot ated ▁equally . ▁For ▁example , ▁if ▁t ▁= ▁ 2 ▁and ▁the ▁ch ord ▁is ▁[ 0 ▁ 3 ▁ 6 ], ▁trans position ▁( clock wise ) ▁will ▁be ▁[ 2 ▁ 5 ▁ 8 ]. ▁In version ▁can ▁be ▁seen ▁as ▁a ▁symmetry ▁with ▁respect ▁to ▁the ▁axis ▁formed ▁by ▁ 0 ▁and ▁ 6 . ▁If ▁we ▁carry ▁on ▁with ▁our ▁example ▁[ 0 ▁ 3 ▁ 6 ] ▁becomes ▁[ 0 ▁ 9 ▁ 6 ]. ▁ ▁An ▁important ▁characteristic ▁are ▁the ▁invari ants ▁which ▁are ▁the ▁notes ▁which ▁stay ▁identical ▁after ▁a ▁transformation . ▁No ▁difference ▁is ▁made ▁between ▁the ▁oct ave ▁in ▁which ▁the ▁note ▁is ▁played ▁so ▁that , ▁for ▁example , ▁all ▁Cs ▁are ▁equivalent , ▁no ▁matter ▁the ▁oct ave ▁in ▁which ▁they ▁actually ▁occur . ▁This ▁is ▁why ▁the ▁ 1 2 - note ▁scale ▁is ▁represented ▁by ▁a ▁circle . ▁This ▁leads ▁us ▁to ▁the ▁definition ▁of ▁the ▁similarity ▁between ▁two ▁ch ords ▁which ▁cons iders ▁the ▁subsets ▁and ▁the ▁interval ▁content ▁of ▁each ▁ch ord ▁. ▁ ▁Re ception ▁ ▁Cont ro vers y ▁over ▁the ▁term ▁itself ▁ ▁The ▁term ▁" aton ality " ▁itself ▁has ▁been ▁controvers ial . ▁Arnold ▁Sch o enberg , ▁whose ▁music ▁is ▁generally ▁used ▁to ▁define ▁the ▁term , ▁was ▁veh ement ly ▁opposed ▁to ▁it , ▁arg uing ▁that ▁" The ▁word ▁' at onal ' ▁could ▁only ▁sign ify ▁something ▁entirely ▁incons istent ▁with ▁the ▁nature