The in-game music which plays at the start of your game (especially annoying if you join late) and towards the end (different if you are winning or losing) is loud, distracting, and completely unnecessary. If someone uses the perk amplify and invests in a headset they should be able to listen to the proper in game sounds without worrying about the in-game music playing at the most inconvenient times.
Lobby music makes it difficult to hear other players.
Create an option to disable in-game music (customisation options in the currently 100% rigid game volume setting in options menu).