Romans employed various non-brass musical instruments to aid soldiers with marching and signalling throughout its extensive history; some instruments included the cornu (horn), tuba (straight metal trumpet), lituus (curved instrument), and buccina (a curved horn resembling a modern french horn) played to provide musical melodies as part of Roman war rituals but primarily utilized for signals during military campaigns; to summon soldiers as to sound off retreat or advance on the battlefield when other methods of verbal communications or visual flags may proved to be unreliable or inaudible