"Open Your Heart" is a plea to a possible love interest. In the lyrics, she urges them to open their heart to her, and implies that all she needs is for them to just allow her in to be loved. She promises to not run away, but that she is willing to work hard to earn their trust. She also shows understanding of the pain they feel, understanding why they are afraid to open up to her. The chorus emphasizes the theme of opening up, as she asks her love to open their heart to her, and that she holds the lock while they hold the key. The bridge emphasizes the same idea, as she says that it won't be hard to open up if they just unlock their hearts. The overall message of the song is that love can be found if both people are open and honest with each other.
The clip Madonna — Open Your Heart can be downloaded for free and without registration.