Gig posters are what bands use to get their fans in the door. What they are not is album or CD covers. The point of gig posters is to sell the music of your favorite band to a specific demographic.
Gig posters are part of the life blood of the modern music era as current technological trends make touring more important than music releases. Bands make most of their money from their shows versus track sells. Often bands don't even control what goes on their album or CD covers because they technically don't own the music. It is the music publishers that do. What makes gig posters special is bands or recording artists do control the gig posters. There is a direct relationship between artwork, the fans, and the musicians in gig posters.
You are to select your favorite band, rapper, recording artist, or orchestra and begin designing thumbnails based upon your love of their music. Remember it is your job to demonstrate your knowledge of their music visually while trying to create new fans.