Guidance on showing Spotify songs on a commercial website

[EchDesign]

My Question or Issue

Hi, 

I have helped build a Christmas game for a client which consists of answering some festive questions, once a user has answered all the questions, we take the answers and use them to inform 'what kind of Christmas song' they are.

We would like to show the resulting song in an iframe on our website and when the user clicks it, push them to our Christmas playlist on Spotify, with that song playing.

The users will be clients of my client and there will be no password protection on the site / it will be open to anyone who has the URL.

Is this possible from a legal standpoint (we know we can do this via the API, but need to know if we breach any copyright or license issues)? We won't allow playing of the song on our own site, it will only display a graphic that gives the user the ability to listen on the Spotify website.