The best part of driving is the freedom to belt out tunes of your choosing. Uber CEO Travis Kalanick would rather you hail a car from his app than tool around town in your own set of wheels, so the company is partnering with Spotify to put control of Uber's sound system in your phone. 

On Friday, you'll have the option to link your Spotify and Uber accounts within the Uber app. When a music-enabled car responds to your ride request, you can pull up your Spotify playlists within a bottom bar inside the Uber app and jam out. The partnership is launching in 10 cities at first, including San Francisco, New York, London, Stockholm, and Singapore, before rolling out worldwide in coming months. Spotify's promotional video below shows the feature in action:

A premium service for paying Spotify users

The new integration requires drivers to get on board by pairing their phones with the car's audio system. The app will tell you if your arriving Uber is able to play your Spotify tunes. The feature won't work in UberPOOL, the company's carpooling service. During a Monday press conference announcing the partnership, Kalanick said that he's already heard good feedback from drivers. If a passenger abuses the privilege by terrorizing a driver with death metal, the driver still calls the shots when it comes to volume.

"If we see tension points, those are things we'll handle in an elegant way," Kalanick said.

There's another catch: You have to pay for a premium Spotify subscription to tap into the new feature. Spotify CEO Daniel Ek said Monday that the streaming app will offer trial subscriptions to entice Uber riders into signing up.

"What we're noticing is more and more people are skipping owning their own cars and going straight to Uber," Ek said. "This is a way for us to reach a younger audience in cities where they're picking up Uber in droves. This is a way for us to get to massive amounts of users in a quick fashion."

The tie-in might gin up some new Spotify subscribers, but it also benefits Uber. This is the first time Uber has personalized the in-car experience. The feature will appeal to music lovers--so basically everyone--but it will also remind Uber passengers that cabs don't let you control the stereo (although cabs also don't surge-price you).

To promote the partnership, Spotify and Uber are throwing parties in the 10 launch cities on Friday with a roster of major musical acts like Andrew W.K., Diplo, and Jake Owen. Those artists may even show up in your Uber and escort you to the party.

If you're using Uber on Android to hail a ride, the Spotify music experience won't be seamless yet. Instead of controlling the playlist within Uber, you'll have to jump over to Spotify and tap Now Playing > Connect > Uber Partner for your tunes to begin. Uber said an app update is coming soon to fix that.

Kalanick and Ek declined to disclose the financial terms of the deal. Click here for more details on which cities and musicians will be participating on launch day.