Ry Cooder and Randy Newman are two quirky California pop artists whose work defies categorization.

Cooder is an adventurous mandolinist/guitarist who works with traditional American musical forms and their ethnic influences. Though he reaches a rock audience, he's not really a rock performer.His versions of gospel standards and Mexican mariachi music, for example, don't strive for exact replications of the originals; Cooder reaches instead for the spirit of the compositions.

His latest album, "Bop Till You Drop" (Warner Bros. BSK 3358) is a collection of R&B material, and evidences Cooder's usual professionalism. The recording's musicianship, arrangements and production (by Cooder himself) are impeccable. He is a tasteful, mature and sympathetic guitarist, joined here by an equally subtle and dedicated instrumentalist, David Lindley. Although Lindley's musical presence isn't emphasized, he and Cooder bolster each other's work skillfully.

The liveliest song on the album is "Down In Hollywood" (the only original composition included, co-written with bassist Tim Drummond) -- sinuous and sensual, a campy tale of scummy nightlife which opens with a steady, throbbing interplay among guitars, bass and drums. (Some listeners may find Cooder's black mimicry, though tongue- in-cheek, patronizing.) Cooder is accompanied here by Chaka Khan, who possesses a wide vocal range and sings most energetically. Cooder and Khan duet on the lighthearted "Don't You Mess Up A Good Thing," which gives her a better opportunity to elongate and bend the song's lines.

"Bop Till You Drop" is billed as "rock's first all-digital recording," meaning that a digital process was used to mold the sound rather than the usual electromagnetic one. This technique is supposed to result in a less distorted, more vivid sound, but the production on Cooder's previous efforts has been so painstaking that the listener scarcely notices the difference.

Randy Newman's songs lean toward ambiguous satire, and his targets aren't strictly defined. Like Cooder, Newman isn't a strong rock artist; he plays the piano and favors slightly schmaltzy melodies supplemented by synthesizers and string sections. His vocals are laconic, bluesy and noncommittal. His compositions reflect both his classical training and his previous employment in churning out commercial pop.

Newman's current release, "Born Again" (Warner Bros. HS 3346), is as irritating and puzzling as its creator intended. His album title mocks the recent popularity of fundamentalism in rock circles, for which he suggests a possible motive in the opening track, "It's Money That I Love." Backing vocals are contributed by, among others, the underrecognized singer Valerie Carter.

"The Story of a Rock and Roll Band" isn't overtly humorous, but it is nevertheless a hilarious effort. Newman recounts the history of the overblown "art-rock" group Electric Light Orchestra, an outfit which specializes in multilayered synthesizer overdubs, strings and massed choruses. Although his musical parody doesn't quite hit the mark, Newman's deadpan delivery of lines like "Johnny played the little violin/Bobby Joe played the big violin" couldn't be funnier.

The best song is "Pretty Boy," an apparent assault on self-styled ethnic toughs. The composition's spare piano playing lays bare its undertone of ominous violence, while Newman provokes a knife-edge eroticism as he threatens and intimidates his imaginary New Jersey punk.

Some of "Born Again's" other selections, though, are quite annoying and troublesome. "Mr. Sheep" seems a satire of people who make fun of bourgeois executives, but becomes stilted and self-conscious. "Ghosts" is reminiscent of music from educational children's television shows; it's a portrait of an elderly, sick man who resents the new children in his neighborhood. "Half A Man" describes a confrontation between a macho truck-driver and a stereotyped gay. Newman starts with an overloaded, saccharine arrangement, taking the truck-driver's side, then jumbles the characters' sexual identities and seems to resolve the story in favor of the gay man.

"The Girls in My Life" satirizes laid-back sagas which enumerate the former lovers of their cowboy-troubador authors. "Had seven women on my mind," Newman yawns lazily (as did Jackson Browne in "Take It Easy").

Newman's compositions are especially appealing to critics who like dangerous rock music, music that jolts the listener. Newman's themes and his use of racial slurs may indeed appear quite daring to a certain audience (white male heterosexuals) but may strike others as demeaning.

But he is an acute and engrossing songwriter. His songs make multiple strands of meaning, and though he's not always fun to listen to, his material demands the listener's constant scrutiny.