▁the ▁dominant ▁A ▁major ▁of ▁Part ▁V ▁to ▁the ▁j ub il ant ▁re - assert ion ▁of ▁D ▁major ▁in ▁the ▁final ▁part , ▁l ending ▁an ▁overall ▁arc ▁to ▁the ▁piece . ▁To ▁rein force ▁this ▁connection , ▁between ▁the ▁beginning ▁and ▁the ▁end ▁of ▁the ▁work , ▁Bach ▁re - uses ▁the ▁ch or ale ▁mel ody ▁of ▁Part ▁I ' s ▁" W ie ▁soll ▁ich ▁dich ▁emp fang en " ▁in ▁the ▁final ▁ch orus ▁of ▁Part ▁VI , ▁" N un ▁se id ▁ihr ▁wohl ▁g ero chen "; ▁this ▁ch oral ▁mel ody ▁is ▁the ▁same ▁as ▁of ▁" O ▁Haupt ▁voll ▁Bl ut ▁und ▁W unden ", ▁which ▁Bach ▁used ▁five ▁times ▁in ▁his ▁St ▁Matthew ▁Pass ion . ▁ ▁The ▁music ▁represents ▁a ▁particularly ▁s oph istic ated ▁expression ▁of ▁the ▁par ody ▁technique , ▁by ▁which ▁existing ▁music ▁is ▁adapted ▁to ▁a ▁new ▁purpose . ▁Bach ▁took ▁the ▁majority ▁of ▁the ▁ch or uses ▁and ▁a rias ▁from ▁works ▁which ▁had ▁been ▁written ▁some ▁time ▁earlier . ▁Most ▁of ▁this ▁music ▁was ▁' sec ular ', ▁that ▁is ▁written ▁in ▁pra ise ▁of ▁royal ty ▁or ▁notable ▁local ▁figures , ▁outside ▁the ▁tradition ▁of ▁performance ▁within ▁the ▁church . ▁ ▁Inst rument ation ▁The ▁scoring ▁below ▁refers ▁to ▁parts , ▁rather ▁than ▁necessarily ▁to ▁individual ▁players . ▁Ad her ents ▁of ▁theories ▁specifying ▁small ▁numbers ▁of ▁perform ers ▁( even ▁to ▁' One ▁Vo ice ▁Per ▁Part ') ▁may ▁however ▁choose ▁to ▁use