yourmoviemusic

Recently I made a piece of music for a customer. This was then automatically added to my gallery and can be seen by potential customers. I don't want this song to show up in my gallery, but I can't delete the song. This is because I did not add the soundtrack to my gallery myself (it is not one of the three self-selected sound fragments under the heading 'audio'). How can I delete this piece of music? Thanks in advance for your help!