The composer Mieczyslaw Weinberg started as a piano prodigy in Warsaw under Szymanowski and might have stayed there if the Second World War hadn’t intervened. He ended up assisting at the Tashkent opera until friends put him in touch with Shostakovich, who got Weinberg to Moscow. There he wrote prolifically (200 songs, 26 symphonies, 17 string quartets, seven operas) and found success with performers like Rostropovich and the Borodin Quartet, though the Cold War prevented a wider fame.
Weinberg died in 1996, still in Moscow.