Max, I don't have an experience with the market, but did you get a detailed explanation on the reason for banning? For example, did you declare content rating correctly? If lyrics may contain inappropriate content for children, you might have to say so.
I understand you've been working hard this to make this possible. And as Jobs offered a legal way to consume digital music, you do so for lyrics. I truly admire your efforts.
Someone at Google might have misjudged your app, or you might have missed meeting what Google requires, act quickly but remain professional and calm.
I hope users can help this app developer to receive additional explanation from Google.