This DLC features a high-quality "jazzy and relaxing" soundtrack for players to listen to while building and managing their cities. That's all there really is to it -- just some extra music for you to listen to while you construct the city of your dreams.
Some players thought the music wasn't "jazzy" or "relaxing" enough for their tastes. Others admitted they only bought this expansion because it is included in the bundle pack.
You enjoy jazz music, and don't want to pull up YouTube or Spotify every time you start the game. Just make sure to preview the music included so you know whether it not it suits your ears.