You could modify this by adding acetate to the front so that the card could sit up for display, or by putting all the decoration on the front panel, if you wanted to. If you fancied turning this into a more "masculine" card E.g. for Father's Day, just substitute the flowers for leaves,musical notes, cogs or omit all together (Or... if your man loves flowers leave it as is!)
If you can't find piano keyboard paper its a reasonably simple exercise to cut a couple of strips and make the keys. Ink the edges with black ink for extra definition.