After receiving early lessons on the organ and in harmony from his father Gaetano, Capocci earned a diploma as a pianist at the Accademia di S Cecilia in Rome. He took a position as organist at St. John Lateran in 1873 and after a visit by Alexander Guilmant, Capocci devoted himself to the perfection of organ technique. As a performer, he was known for his fine taste in registration and for his phrasing and musicianship. His compositions are mainly for the organ and include a fantasia for the consecration of the organs at St. John Lateran.