Spotify has been rolling out a number of features over the past year that encourage users to lean back and let the service handle the task of picking the next track. It created a feature for running that picked songs to match your pace. And its Discover Weekly playlists are the pinnacle of algorithmic personalization. Today it's introducing a new feature on mobile, Party, that tries to pull off a similar trick.

Party automatically beat-matches tracks and blends one into another so the music never stops and the transitions sound smooth. That's a crucial addition because, no matter how good your previous Spotify playlists were, you couldn't avoid awkward gaps or abrupt shifts without manually standing at attention to handle the transition between each song.

Like the recently departed Songza, the new Party mode will let you chose the flavor of the music based on genre and mood. You can elect to host a chill techno party or a raging salsa throwdown. And as the energy of the party shifts throughout the evening, you can match the vibe with a "mood tuner" that adjusts the song selection.

Party mode is premiering with a new 120-track playlist from Diplo, and Spotify is promising there will be more original mixes coming soon. It's a little unclear how this mood tuner would work if you choose one of the playlists made by celebrity DJs like Diplo, but for the algorithmically generated mixes that simply match your chosen mood and genre, the idea is to produce an endless stream of tunes whose vibe can vary on command. The feature rolls out today on Android and iOS (sorry desktop DJs you'll need to pull out your phone).