Original sentence: However, he also enjoyed personal and artistic support from a new generation of Russian performers, notably Sviatoslav Richter and Mstislav Rostropovich and for the latter he composed his Symphony-Concerto
Edited sentence: However, he also enjoyed personal and artistic support from a new generation of Russian performers, notably Sviatoslav Richter and Mstislav Rostropovich and for the latter he composed his Symphony-Concerto, perhaps his most personal work to be completed in the last five years of his life