Prince's Heirs Want to Crack Open Music Vault

Prince's music vault has hours and hours of unreleased music locked inside, and some of his heirs want the world to hear it -- and probably for a price.

Sources close to Brianna and Victoria -- Prince's niece and grandniece, who stand to inherit the share of their deceased parents -- tell us the girls are anxious to hear the tunes and then devise a release plan.

And we're told the girls have the support of some of the singer's siblings.

Brianna and Victoria say the point of releasing the music is to share it with his fans, but it begs the obvious ... it's ultimately all about making money.

The girls, repped by attorney Andrew Stoltmann, and several siblings also would like to turn Paisley Park into a museum -- a la Graceland -- again, there will almost certainly be a price of admission ... with the goal also being not to make anything seem tacky or exploitative.

Now here's the rub. Multiple sources tell us the heirs are already at each other's throats and war has broken out on several fronts. Tyka has drawn a line in the sand. As far as she's concerned, it's her way or the highway.