Battle Musicians

[Lusitani 5th Empire]

command > horn blower uses instrument/horn > troops would then execute the movement.

Trappings of War - banners, war horns, iconic standards (eagle standard etc), and other period instruments

Exactly, a different horn/instrument/war cry sound for each faction would be great. The problem is that you are always giving commands and it becomes annoying. To solve this, the sound should only trigger for certain commands, the main ones (at least charge and retreat), and in case of repeating the same command within x seconds the sound would not repeat.
If devs eventually introduce banners to the battlefield, a banner carrier for each group you give orders to could do some fancy to signals visually indicate the command.

Also some battle shouts from the NPC troops would be fine, just some random stuff like "Hold ground" or whatever. This would be cool.

Also this could happen and I think it would be immersive and non invasive, just have proper sound occlusion in the game so that a man 50 meters ways doesn't sound like he's screaming next to you.

Something like this would be very cool.

+1 To what Kentucky says.

Play these two videos at the same time

A little more love in this section wouldn't hurt. The problem I see is the current situation with the pandemic. If we didn't have this, I'm sure Ugurcan Orcun could gather a good number of football fans, record them on a field with ambient sound and then process the tracks digitally.

 

[Terco_Viejo]

Honestly, I don't see a usefulness or practicality in the figure of musicians as a kind of unit as the OP argues. That said, as we've discussed before (last debate here) in other threads, having faction-specific instrument sounds when giving a battle order seems much more interesting to me.

I share this again:

Verbal Command > *Faction Sound > Troops Execute Movement

(*) F.e.

Empire-> Roman Cornu
Battania-> Carnyx
Vlandia-> War Horn
Aserai-> Būq al-nafīr
Khuzait-> Guangu Drum
Sturgia-> Olifant

Lastly, as for "emboldening" troops, I would find something similar to what this mod provides more interesting. The general/leader is the one who encourages his troops by means of a cheering action with a radius of action similar to the inspire order in total war.

 

[AndrewArt]

so you want something like this. I suggest also adding it to multiplayer for more immersion

 

[MostBlunted]

so you want something like this. I suggest also adding it to multiplayer for more immersion

Nice Video!

 

[Sanctumm]

Wuld love it the music actually coming from NPC´s - and multiple songs/melodies at once - and once they get chopped down their individual music stops <3 would love it
"Stop that trumpet horn yo empire filth! i´ll TAKE your head"