1830–31, he became one of many expatriates of the Polish "Great Emigration." In Paris, Chopin made a comfortable living as a composer and piano teacher, while giving few public performances.
Though an ardent Polish patriot, in France he used the French versions of his names and eventually, to avoid having to rely on Imperial Russian documents, became a French citizen After some ill-fated romantic involvements with Polish women, from 1837 to 1847 he had a turbulent relationship with the French writer George Sand (Aurore Dudevant). Always in frail health, in 1849 he died in Paris, at the age of 39, of chronic pulmonary tuberculosis. Chopin's extant compositions were written primarily for the piano as a solo instrument. Though they are technically demanding, his style emphasizes nuance and expressive depth. Chopin invented musical forms such as the ballade and was responsible for major innovations in forms such as the piano sonata, waltz, nocturne, étude, impromptu and prelude. His works are mainstays of Romanticism in 19th-century classical music.