Background question

This is probably a very silly question. Our church is use to having each song having it's own background.

I have played around with Openlp for a while now and I know that you can create themes but we have about 1700 songs in our database with about 100 or so backgrounds.

The way I see it in order to use the background we will have to create a theme for each of our backgrounds, is this right? So we will end up with over 100 themes?

Thanks for the help