How to make music transition with pause?

Question

Unity

The idea is this - music plays in the menu and select levels

AudioMusic.clip = musicMenu;
AudioMusic.Play();

after the level has already been selected, a short melody (3 seconds) should be played and after that other music (of the game itself) will turn on.
here I have 3 tracks
musicMenu
musicTransition
musicGame

And when I click on the level selection to go to the game, the StartGame () method is triggered, all actions start immediately there, but I somehow need the musicMenu to fade out when this method starts, then I played musicTransition in the game while there was a pause, and then musicGame turned on and everything in the game started, tell me how to do this?