We are removing the functionality to embed tracksets using the Spotify Play Button on July 15th 2017.

The Spotify Play Button allows for embedding tracks, albums, artists and playlists. It can also embed a list of tracks passed as a parameter, which was useful to create a dynamic playlist. These lists of tracks are not supported in the Spotify clients, which default to showing a view for a single track, instead of the list.

We recommend that you use Spotify Play Buttons for playlists instead. With the Web API you can create playlists dynamically and get the benefits of being fully integrated with all Spotify clients. This means users will be able to search for your playlists and subscribe to them.

If you have any questions or need support, feel free to contact us on @SpotifyPlatform.