I'm not sure how good something like this would turn out. CSGO is one of those things that isn't too hardly stylised, therefore it can have a bigger variety of weapon skins, gloves, and models without breaking up crusial parts of the game's identity. But compared to Counter Strike, Tf2 is heavly stylised. The structures of matches are also very different, while csgo matches are short and snappy, tf2 matches tend to drag out, sometimes even being infinite if nobody contributes to winning in maps like Two Fort.

So the first part is going to be "Stylisation" as that is a crusial part of tf2, visual style, class siluets, team colors, weapons, voice lines, maps, colors, etc. Many things like unusuals, cosmetics, taunt effects already break up the game so the question is, "Should music kits in tf2 get heavly stylised, or should it be like in csgo?" In the end, the answer is somewhere around the middle, to give variety, but also, there shouldn't be a Doom 2016 music kit for tf2.

The second part is the "game's music". Something that this music kit showcases very well. Let's say we gone with staying true to tf2, but then there is also a problem with that. Music kits are so good because of their big variety, therefore, this also wouldn't be the best option either.

The next one up is "gameplay" and the most interesting part too. Tf2 is a game where sound is VERY important, something that detecting spies heavly relies on. Not to mention, tf2 is already very busy when it comes to 5 soldiers spamming rockets down into a choke point, and that is the same with sound, but sound in something like tf2 still holds valuable information. You can hear someone saying spy, or the medic shouting his über being ready, or über being deployed, you can hear nearby sentry nests, a heavy with a reved up minigun and so on. Although, I have to admit, sound is not the most important part of tf2, and it's mostly situational. So adding to sound could be a bad thing, while it could also not bother any waters, which honestly just depends on what settings you're using.

Another part that we have to take into consideration is "fun". In my opinion, music kits could work in tf2 and be fun, but not without breaking up tf2's musical style, but on the other hand in csgo, nobody can really hear your music kit, except in certain moments. Cosmetics and unusual effects can be a problem because everyone can see it and that is why it ca be such an issue, that is why signs in tf2 is such a problem too. And obviously, what would be the porpuse if that wasn't the case, but at the same time it adds to things that are sometimes just straight up wacky, but other times problems. But music kits are different in this regard, therefore it also wouldn't disturb too much as it is costumisable in a way that fits you without making anyone mad. And if you don't like it, then you have the option to don't, unlike with cosmetics or particle effects that people WILL wear and use so you can still see them.

So in conclusion, it could work (although, that would require a lot of work because Valve doesn't like to work on their game anymore), but not without breaking up the style of tf2 at some point for it to be fun, but it would also add a costumisability that you could use as your own. It's like having beliefs and such "as long as you keep it to yourself and you don't go out of your way to actively try to convince others, nobody cares" and that is a good thing. It would also be really unique to tf2. So it gets a yes from me, but I am still not sure if my opinion is 100% right because hey, it's just my opinion, but others should be able to see what is right for tf2.




So let's get to ideas!:

Music kits work passively when a certain action is taken, or when something is idol.
Right now we have a round start, round begin, Point captured, Round ending, CTF Stingers, and a Payload Progression.

Because tf2 is a game with so many game modes, each music kit should be big without telling you information that you wouldn't have know without the music kit (basiacally pay to win).
With that in mind, here are some ideas.

Envirometnal action:
CTF:
CTF Intelligents pick up (Blue side, Red Side),
CTF Intelligents drop (Blue side, Red side),
CTF Intelligents captured (Blue side, Red Side)
CTF Pursuing enemy with intelligents (activated when taking a shot at the enemy)
CTF Being pursued with intelligents (activated when being shot with the intelligents)


Attack/Defend:
First Control Point Captured (Red side, Blue side)
Second Control Point Captured (Red side, Blue side)
Last/Final Control point captured (Red side, Blue side)

The rest of the control point ones:
Control point captured (Red side, Blue side)
Control point lost (Blue side, Red side)

Payload:
Pushing cart calm
Pushing cart threathened (activates when taking a hit while pushing the cart, each hit adds 30 seconds into the song, being hit again repeats the 30 timer, adding the possibility of the song looping).

MVM:
Wave Start
Wave End
Bomb being close
Tank being close
Wave lost
Final wave special start
Final wave song
Match won

Special actions:
Über ready
Über deployed (Both for medic and the target who is being übered)

Killstreak:
On Killin Spree (5) (mvm:20)
Unstoppable (10) (mvm:40
Rampage (15) (mvm:60
God Like (20) (mvm:80
Still God Like (every 5 past 20) (mvm: every 20 past 80)
Killstreak Ended

Global:
Game Lost
Game Won

This is all I could scrapp together today, but what do you think, and do you got any ideas for what parts of tf2 should it costumise? I would personally love some different music creator's music, but also a Half life themed, Combine themed, Portal themed, Left 4 Dead themed, csgo themed music kits. Also, having an offical tf2 one, made out of mixed versions of the original tracks to fit into a music kit.