Also to a first approximation we can treat all music as roughly interchangeable and we can measure the 'amount' of music eg by runtime or by song, so compulsory licensing can set some arbitrary fees.
You can perhaps do something similar for video, but it's hard to do that for all copyrighted material. Eg for a video game a single sprite has a very different value than some modules in the game's engine.
Try seeing how many Beatles songs you can include in another work that you distribute internationally and let me know how that goes.