As it turns out, when the icon is selected, it plays the exact same "NaNaNaNaNaNaNaNaNaNaaa" as Kid Icarus Uprising.
What the hell?
It's supposed to be that way. i got it a free download code as a pre-order bonus for pre-ordering it at Best Buy last year and when i downloaded it to my 3DS it had the same intro music. no worries! lol.
"OldSchoolGaming4Life" on YT/"90sRetroGaming" on mariokartwii.com