9 6 8 , ▁ 2 0 0 8 ); ▁Der ▁Unter bro ch ene ▁Ged an ke ▁( 1 9 8 4 ). ▁R . ▁Murray ▁Sch a fer ▁( born ▁ 1 9 3 3 ): ▁Th ir teen ▁string ▁quart ets , ▁as ▁of ▁ 2 0 1 5 ; ▁the ▁sevent h ▁quart et ▁includes ▁a ▁sop rano ▁part , ▁the ▁fourth ▁and ▁nin th ▁include ▁t ape ▁parts . ▁ ▁Di agn osed ▁with ▁Al z heimer ' s ▁D ise ase ▁in ▁ 2 0 1 5 , ▁Sch a fer ▁composed ▁the ▁brief ▁String ▁Quart et ▁No . ▁ 1 3 , ▁which ▁he ▁subt itled ▁' Al z heimer ’ s ▁Master pie ce ', ▁for ▁the ▁Qu atu or ▁Mol in ari . ▁Harrison ▁B irt w ist le ▁( born ▁ 1 9 3 4 ): ▁N ine ▁Mov ements ▁for ▁String ▁Quart et ▁( 1 9 9 1 – 9 6 ), ▁String ▁Quart et : ▁The ▁Tree ▁of ▁Str ings ▁( 2 0 0 7 ); ▁Ho quet us ▁Ir vin us ▁( 2 0 1 3 )( short ▁work ▁for ▁the ▁Ar d itt i ▁Quart et ' s ▁for ti eth ▁anni versary ); ▁String ▁Quart et ▁No ▁ 3 : ▁The ▁Sil k ▁House ▁Se qu ences ▁( 2 0 1 5 ). ▁Peter ▁Max well ▁Dav ies ▁( 1 9 3 4 – 2 0 1 6 ): ▁String ▁Quart et ▁in ▁One ▁Mov ement ▁( 1