Howard Ashman, the lyricist who packed so much coiled, wicked wit into the Disney cartoon hits The Little Mermaid, Beauty and the Beast, and Aladdin, would probably never have okayed the kissy-kissy rhetoric that frames a luxe new four-CD boxed set, The Music Behind the Magic: The Musical Artistry of Alan Menken, Howard Ashman & Tim Rice. Do we really need breathless assertions that the prepubescent Ashman was ''a legend'' in his neighborhood for putting on backyard musicals? Such puffery sounds less like Ashman, who died of AIDS in 1991 (hence the assist from Rice), than like melodist Menken. Menken was always the sweeter, McCartneyesque foil to Ashman's Lennonesque wit and he's the sole producer of this tribute.
Still, once you get past the self-congratulations in the liner notes, the tracks themselves expand the original soundtrack playlists with copious work- tape, demo-version, and scrapped-song renditions, sung mainly by the composers. Biggest discoveries: Ashman's rough vocals were virtual blueprints for sea witch Ursula and candlestick Gaston, and loads of scabrous wit were snipped from Aladdin (like a ''Prince Ali'' couplet that calls Turks ''real jerks'' and a bitchy, Jewish-American Princess anthem for Jasmine). Biggest lesson learned: Nothing has ever leavened the Disney taste for spoonfuls of sugar so deliciously as Ashman's soupçon of spite. A-