The helicon is a brass musical instrument in the tuba family. Most are BB♭ basses, but they also commonly exist in EE♭, F, and tenor sizes, as well as other types to a lesser extent.The sousaphone is a specialized version of helicon, differing primarily in two ways: a Sousaphone bell is shaped to face forwards and has a larger flare, a Sousaphone has a "goose-neck" leadpipe which offers greater adjustability of mouthpiece position at the expense of tone quality, while both instruments have circular shapes and are designed to be worn over the shoulder.
The instrument is very popular in central and eastern Europe and is a common choice for military fanfares.
Its range is two octaves below that of a cornet.