You have to be a Gold member in order to have the ability to upload music to your profile. You can upload music by clicking My Profile>Edit My Tune. You can upload a maximum of 3 songs, each having a maximum filesize of 5MB. If you successfully uploaded your songs and they do indeed have a filesize less than 5MB, and the music is still NOT playing, you have to re-upload your songs. To re-upload the songs go ahead and delete the songs you uploaded, then upload them again. Be sure to allow the uploading process to finish before you continue using Mingle City, as doing so will cause an upload failure.