He toured as a pianist and was known as a composer and arranger of popular Spanish folk music. Nin was a member of the Real Academia de Bellas Artes de San Fernando of Madrid and the French Legion of Honor.
He was son of the Catalan writer Joaquin Nin Tudó and Àngela Castellanos Perdomo, a Cuban from Camagüey. Nin studied piano with Moritz Moszkowski and composition at the Schola Cantorum (where he taught from 1906 to 1908).