As a Drum major I am very interested in this discussion.
It may of been even earlier, there is a connection back to Greek and Roman period of a Band leader of flutes, Horns and drums wearing clothing relating to Mercury/Hermes and carrying a Caduceus(He is the patron god of financial gain, commerce, eloquence (and thus poetry),messages/communication (including divination), travelers, boundaries, luck, trickery and thieves; he is also the guide of souls to the underworld
Mercury's caduceus (was a mace entwined with cords) in his left hand ( a caduceus is also represented with heralds who also carry a similar mace in thier left hand to represent messenger). This is the root word of Cadence, or marching.
There are a few archeological images and later paintings reflecting this.
first a cadence
Hermes
Trajans column, note the Hermes figure behind band
1614—Dresden, Germany: An image documenting a procession in honor of the baptism of Duke August depicts two trombones and a cornetto, followed by a person dressed as Mercury
Ottoman band
The Coronation Procession of King James II and Queen Mary of Modena. 1685
so a few early examples
cheers
matt