I couldn't find this on youtube anywhere, so i decided to upload it.
Find the unofficial soundtrack here:
http://mlpost.tumblr.com/

Download MP3 Here:
https://soundcloud.com/soniclightbolt94/mlp-bgm-its-time-to-party

From - S2xE09 Sweet and Elite

Background Image:
http://slb94.deviantart.com/art/Party-Time-441283126