Should we have a band?

We are struggling to decide whether to have a band at our wedding reception. We have the option as it's a friend's band and it will be either free or greatly reduced in cost. Things to consider: - They play exactly my fiance's taste in music - It won't cost much - It will make the friend happy to be included - The friend is my boss - The style of music clashes significantly with our 1930s vintage theme (we are having guests dress to the theme and our venue is also vintage styled) - It's the opposite of my taste in music - Some guests will love it, some will hate it - They won't be able to play our first wedding dance song as that will be jazzy (but we can play this over speakers) What should we do?