Why do some of Spotify's playlists change songs and then revert to their "default" state?

[Pluvillion]

I noticed the Happy Hits! playlist keeps changing day after day. Some songs stay, some songs are removed, some songs "cycle", and some songs return after a day or two. AJR's Way Less Sad is always at the top, but sometimes it gets replaced by AUSTIN's In Betweenin' or Bastille's Thelma + Louise, and sometimes the song gets removed in the playlist entirely.

Yesterday the playlist had a completely different setlist save for a few recurring songs. Today the playlist is the same as when I first discovered it a few months ago.

Which leads me to the question: is there an algorithm that sorts the songs in the playlist? Is it based on what I'm listening to or is it an automatic process?

[Taylith]

Hello @Pluvillion , it's an interesting question you bring up.

What I can say is the playlist isn't user-specific so no, it does not depend on how anyone plays it.

I can't get into detail on the algorithm(partly because I don't know how it works myself 🙂 )but it most probably works depending on trending tracks which fit the theme at the time.

It's an automatic process.

Thanks and take care 🎼🖤