Recently, I was commissioned to design promotional artwork for a couple music tracks, as part of a UK radio push.
There were no strict guidelines, however there are always some design limitations when creating something that needs to grab the viewer’s attention, while also not being too complex. The design needs to be optimized to look great on a small digital library playlist (think mobile phones, iTunes, Pandora). The artwork should also resemble the tone and mood of the song.
Looking at the difference between the “Brunette” artwork and “Midnight Hour” artwork, I think it’s easy to tell which song has more of an adrenaline rush.