In an early post, I mentioned that the Sousaphone is essentially an adaped Helicon bass, only much larger and with its big bell pointing straight up. I also noted that Helicons were used, in part, by cavalry bands, meaning they were played while riding horseback.
Trying to imagine how that would work? Check out this photo I came across in the October 1922 edition of C. G. Conn's Musical Truth (vol. 11, no. 31):