Victor de Sabata confided to Walter Legge, "If the public could understand, as we do, how deeply and utterly musical Callas is, they would be stunned", and Tullio Serafin assessed Callas's musicality as "extraordinary, almost frightening."
Maestro Victor de Sabata sa zveril Walterovi Leggemu: "Ak by publikum dokázalo pochopiť, tak ako to dokážeme my, aká hlboká a dokonale muzikálna Callasová je, bolo by ohromené", a maestro Serafin hodnotil Callasovej muzikálnosť ako "výnimočnú, takmer až desivo."