Hey @12164400754, thanks for posting here on the Spotify for Developers board!
Great question! - The search operators you can use are: 'genre', 'label' and/or 'year'. Searching by popularity is not supported (yet!). If this is something you'd like to see, I recommend creating a new idea on the Ideas board. That way, Spotify can keep track of your feedback.
Feel free to give me a shout, if you have any questions!
Have a great day,
HuboRock Star 16
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