If you like the girl seriously just stick with her. You can develop a Springsteen support group on the side, without her. The other option is to clone yourself a sister, and feed her Springsteen daily.
In all this discovery might mean you may want to reevalute how compatible you two really are---like maybe you've been a little blind the past 6 months? But I wouldn't sweat if otherwise you have a good relationship. You wouldn't want to date your clone anyways, would ya?
Alt option is to get everyone in your relationship their own mini-iPod.