▁Fe u ermann ' s ▁un tim ely ▁death ▁it ▁took ▁seven ▁years ▁for ▁He if etz ▁to ▁collabor ate ▁with ▁another ▁cell ist , ▁Greg or ▁P iat ig or sky . ▁ ▁Art ur ▁Rub in stein ▁was ▁equally ▁em ph atic : ▁" He ▁became ▁for ▁me ▁the ▁greatest ▁cell ist ▁of ▁all ▁times , ▁because ▁I ▁did ▁hear ▁Pablo ▁Cas als ▁at ▁his ▁best . ▁He ▁( C as als ) ▁had ▁everything ▁in ▁the ▁world , ▁but ▁he ▁never ▁reached ▁the ▁mus icians hip ▁of ▁Fe u ermann . ▁And ▁this ▁is ▁a ▁declaration ." ▁If ▁one ▁can ▁grade ▁( appro xim ately ) ▁music ▁playing ▁into ▁technical , ▁art istic , ▁philosoph ical ▁and ▁divine ▁levels , ▁in ▁his ▁full ▁m atur ity , ▁Fe u ermann ▁had ▁touched ▁on ▁the ▁philosoph ical ▁level . ▁Given ▁enough ▁time , ▁he ▁might ▁touch ▁on ▁the ▁divine ▁level ▁on ▁playing ▁c ello . ▁His ▁un tim ely ▁death ▁never ▁allowed ▁him ▁to ▁reach ▁there . ▁Both ▁He if etz ▁and ▁Rub in stein ▁were ▁long time ▁tri o ▁partners ▁with ▁Fe u ermann . ▁During ▁his ▁first ▁tour ▁of ▁the ▁United ▁States ▁in ▁ 1 9 3 5 – 3 6 , ▁Fe u ermann ▁re aped ▁enthus i astic ▁reviews ▁from ▁music ▁critics . ▁After ▁a ▁ 1 9 3 8 ▁Prom s ▁performance ▁in ▁London , ▁critic ▁Re id ▁Ste ward ▁of ▁The ▁Str ad ▁wrote ▁" I ▁do ▁not ▁think ▁there ▁can ▁any ▁longer ▁be ▁doubt