▁was ▁prohib ited ▁by ▁the ▁Commun ist ▁Party ▁for ▁being ▁too ▁m ourn ful ▁for ▁the ▁Soviet ▁public . ▁Among ▁Lok sh in ' s ▁own ▁compos itions ▁which ▁he ▁never ▁heard ▁performed ▁are ▁the ▁cant ata ▁M ater ▁Dol or osa ▁( 1 9 7 7 ) ▁on ▁vers es ▁from ▁Ak h mat ova ' s ▁Re qu iem , ▁which ▁was ▁prohib ited ▁in ▁the ▁Soviet ▁Union ▁at ▁the ▁time . ▁In ▁ 1 9 8 1 ▁Lok sh in ▁had ▁passed ▁the ▁score ▁of ▁M ater ▁Dol or osa ▁abroad ▁to ▁Rudolf ▁Bar sh ay . ▁However , ▁it ▁was ▁impossible ▁for ▁Bar sh ay ▁to ▁perform ▁this ▁composition ▁in ▁the ▁West ▁in ▁view ▁of ▁the ▁un predict able ▁consequences ▁this ▁could ▁have ▁had ▁for ▁Lok sh in . ▁Bar sh ay ' s ▁performance ▁of ▁Lok sh in ’ s ▁Re qu iem ▁at ▁the ▁closing ▁of ▁the ▁IV ▁International ▁conference ▁" Res istance ▁in ▁the ▁Gul ag " ▁( M osc ow , ▁ 2 9 ▁May ▁ 2 0 0 2 ) ▁was ▁the ▁first ▁essential ▁step ▁on ▁the ▁way ▁to ▁Lok sh in ' s ▁post hum ous ▁re h abil itation . ▁ ▁According ▁to ▁Lok sh in ' s ▁son , ▁the ▁composer ▁was ▁the ▁victim ▁of ▁a ▁cal umn y , ▁and ▁the ▁real ▁source ▁of ▁the ▁charge ▁that ▁Lok sh in ▁was ▁an ▁inform er ▁was ▁not ▁the ▁former ▁Gul ag ▁prisoners , ▁but ▁St alin ’ s ▁secret ▁police ▁themselves