In general,
Gvynblade, such "scenes" are generally a composite of individual elements in the engine.
1.) Each of the "musicians" is likely an individual "actor" (animated NPC model and texture set) that must be placed in the game world manually, then configured for proper facing. Additionally, it may be necessary to manually assign and "idle" animation package to it (...standing around and chatting, walking about a certain area, looking at a market stall, playing a musical instrument, etc.)
2.) The veranda behind them is likely a separate "static" mesh and texture package that must be individually placed and positioned.
3.) The sound of the music itself is a separate sound activator that must be assigned a central point in 3D space, and then perhaps configured to decide the radius of its effect (when the player begins to hear the music "fade in" as they approach).
I don't have any experience with TW3 modding, so I can't tell you exactly how it works here, but pretty much every game works as I've described above. It will almost certainly require the use of modding tools to add the scene in your video. Is there a simple, in-game, console command that would work like
PlaceAtMe "Minstrels_Outdoor" 0045678 ? I don't think so.