Apple TV 4k music file transfer

Apple TV is not a storage device, it only streams media. In short it cannot store your music. However if you use a music service like Spotify, Apple Music or Pandora there are apps that can help you stream music.

You can reference https://support.apple.com/guide/tv/library-atvb9ed3ea39/tvos

https://support.spotify.com/us/article/spotify-on-tv/

https://help.pandora.com/s/article/Pandora-on-Apple-TV-1519949301619?language=en_US

Apple TV is for streaming. Storage on the device is for apps, not for content.

You may use Home Sharing to have it connect to a networked computer, and play music files e.g. using the Computers app.