''Park'' ranger Trey Parker cowrote most of the 12-song score with established composer Mark Shaiman, and these two don't waste time in getting the mock Menken & Ashman riotously under way. Anyone who's seen ''Beauty and the Beast'''s Belle describing her provincial life will recognize the roots of ''Mountain Town,'' and even Satan gets a yearning ballad, wondering about life ''Up There,'' à la ''Little Mermaid'''s ''Part of Your World.'' It's not just Disneyana on the block: ''What Would Brian Boitano Do?'' is prime variety-show disco, while the do-si-do Coplandisms in ''Uncle F**ka'' suggest ''Oklahoma!'' on crack, with an inspired farting interlude that seems ripe for an Agnes de Mille dream ballet.
The disc is filled out by less satisfying ''interpretations'' of the score by hip-hop and rock acts, from Kid Rock to Rush. When rappers turn Parker's profane ditties more obscene still while jettisoning the orchestration's satiric juxtaposition, it's distressingly close enough to standard hip-hop fare that the joke sours, especially when you imagine kids committing them to memory. You should probably have to show your Sondheim Fan Club card, if not proper proof of age, to buy a copy.