the roman horns changed according to period as well as region, roman history is pretty vast and complex and their technologies changed as time went by and as they were influenced by the places the conquered. same goes for the use of drums for war... only very recently (compared to the history of the drum) were instruments use for battle communication; before, it was very straight forward use: to inspire valor in your soldiers or fear in the enemy.
btw, there's also a simple experiment you can do at home if you have big enough speakers... you can place a bowl of water in a metal bowl over the speaker's woofer, and play music, accordingly the water will vibrate with specific geometric shapes according to the frequencies of the specific songs you play. you need to get the water level right in the bowl so it won't spill over and also so that the geometric shapes can be more easily seen.
be good
btw, there's also a simple experiment you can do at home if you have big enough speakers... you can place a bowl of water in a metal bowl over the speaker's woofer, and play music, accordingly the water will vibrate with specific geometric shapes according to the frequencies of the specific songs you play. you need to get the water level right in the bowl so it won't spill over and also so that the geometric shapes can be more easily seen.
be good