The story of Rachmaninoff's life and career is perhaps one of the most unusual among those of famous composers. Not only did Rachmaninoff live in two centuries, experiencing many changes in music, literature, theater and art, but he also witnessed momentous changes in Russia, as well as the impact of world events on Russian history: the end of the Tsar's Russia with the Revolution of 1917 and the First and Second World Wars. Numerous identified and unidentified sources have called Rachmaninoff "the last Romantic of the twentieth century," implying that his style remained firmly in the Romantic tradition throughout his career, untouched by twentieth century musical influences. In fact, though, his style did evolve, but it did so in ways which were so smooth and subtle that the changes were almost unnoticed.This book focuses on the evolution of Sergei Rachmaninoff's musical style as illustrated by his four Piano Concertos and the Rhapsody on a Theme by Paganini, comparing different stylistic features such as orchestration, harmonic and melodic language, and the relationship between the piano and the orchestra.