You can play MP3s in your scene. While Vivaty doesn't accept uploads right now, you can link to any MP3 that's available on the Internet.

Click on "My Stuff" and select "Audio" objects.

These objects will play MP3 files (and some WMA files). Add the object to your scene, and then select the Properties of the object.

In the Properties, add each link to each song. You can create and reorder songs in your playlist after adding them.

You can also edit the object so it Autoplays the music under the General tab.