"To lose a man like this is terrible. For us he was a poet, a painter, everything," Lilian Hochhauser, Richter's London agent for more than 35 years, said. "But the recordings will live."
Richter, born of ethnic German stock in Zhitomir near Kiev in 1915, had lived in Paris and Germany in recent years. He had been in poor health since a heart bypass operation two years ago and had not performed in public for some years.
Catherine Trautmann, the French Culture Minister, described him as "one of the greatest virtuoso pianists of our time", adding in a statement: "Svyatoslav Richter has left us. The world of the arts is in mourning."
Richter returned to Moscow with his wife Nina Dorliak about a month ago; he was rushed into the Central Clinical Hospital on Thursday.
His father, a pianist and composer, gave him his first music lessons and by 1933 Richter was accompanying opera - his first love - in the Black Sea city of Odessa. He composed from the age of eight but stopped at 20. For 10 years from 1937 he studied at the Moscow Conservatory and by the Fifties he was one of the world's top touring performers.
His repertoire encompassed the great classics of European music, including his fellow Russian and friend Sergei Prokofiev.
Alain Plains, a French pianist who knew Richter, said: "When he played it was as if you were hearing for the first time a work you had heard a thousand times."Reuse content