It might seem stupid but the future MP games should have a catchy theme song, like the current Pokemon theme song.
Problably what Yoshiman222 said.Yoshiman222 said:All Mario Party games should just stick to having their own.
It fits better, so you have a better knowledge of the game you're playing (If you are not looking, that is)
...but I mostly like how they have their own theme.
Plus ~ it would be weird for a spin-off Mario series to get it's own theme... Mario doesn't even have a (single) theme himself.