More Beasties

Another fascinating tidbit from the Beastie Boys' Check Your Head album that I've read in Brian Coleman's book Check The Technique concerns the recording of their single 'So What'cha Want':
Mario Caldato Jr.: That was the last song, the one that sealed the deal and let us know the album was ready. The original of that song is underneath, and the Beasties just replayed it over the top of it [Mario plays original song over the phone but makes author promise not to reveal what it is].
It might've been Rick Rubin who said something about how the best singles come together near the end of the process of writing or recording an album, so it was interesting to learn that was the case with this track -- which I listened to a lot in '94.

I'd like to know what the track the Beastie's covered was. I've heard of this technique of building a song on top of another, then removing the foundation described as scaffolding. Here's a live version of the track featuring DJ Hurricane and Cypress Hill: