I guess he wishes that she would've taken his feelings with her when she left or at least changed the locks to his "music box" because he thinks of her when he plays certain songs I suppose. He had strong feelings for her of some kind and did not keep a leash on them and trampled on her despite her hints of disapproval. Now she's gone so he resorts to music for comfort. He knows the heart is for bleeding and it sounds like he has no regrets because to find out, one has to act out. Then he rambles about piecing together a serenade for this woman. He explains what had happened in the last part of the song. He offered up his heart to a girl he liked before it was asked for or even just simply invited. He continues to play his favorite songs for a broken heart.
I guess he wishes that she would've taken his feelings with her when she left or at least changed the locks to his "music box" because he thinks of her when he plays certain songs I suppose. He had strong feelings for her of some kind and did not keep a leash on them and trampled on her despite her hints of disapproval. Now she's gone so he resorts to music for comfort. He knows the heart is for bleeding and it sounds like he has no regrets because to find out, one has to act out. Then he rambles about piecing together a serenade for this woman. He explains what had happened in the last part of the song. He offered up his heart to a girl he liked before it was asked for or even just simply invited. He continues to play his favorite songs for a broken heart.