POP MUSIC REVIEW : Nothing Like the Real Thing : Nineteen singers and groups toast country music and rhythm & blues with very mixed results at the Universal Amphitheatre.

MCA Records’ “Rhythm, Country & Blues” on Wednesday at the Universal Amphitheatre was a classy, warm, spirited affair that offered a welcome twist on the entertainment industry’s growing emphasis on career achievement salutes.

Instead of honoring a single performer, the concert brought together 19 singers and groups--from Natalie Cole and Reba McEntire to the Pointer Sisters--to toast two of the richest strains in American pop music: country and rhythm & blues.

Expanding the concept of a recent MCA album of the same title, the idea was to show how country and R&B--though; long perceived as appealing almost exclusively to white and black audiences, respectively--have a rich, overlapping tradition.

Several of country music’s defining figures, including Jimmie Rodgers and Hank Williams, were greatly influenced by the blues, while many soul greats, including Ray Charles and Al Green, either drew upon or recorded country songs.

So it felt quite natural Wednesday when the country and R&B; artists joined on stage to sing songs from their respective fields, backed by a mixture of rock, country and blues musicians led by Don Was, who produced the “Rhythm, Country & Blues” album.

Despite the good intentions, the performances themselves didn’t always live up to the imagination of the concept during the 90-minute set. Not that the singers--including such pairings as Clint Black and the Pointer Sisters on “Chain of Fools” and Allen Toussaint and Glen Campbell on “Southern Nights”--were entirely to blame.

It’s hard to create magic--or even measure up to the original versions of some of the classic songs--when singers are just doing one or two numbers each in a show whose keep-things-moving pacing was dictated by the requirements of television taping.

Vince Gill and Gladys Knight--two of the best voices in contemporary pop--were finished with “Ain’t Nothing Like the Real Thing” before they seemed even warmed up.

The bigger hurdle was the memory of the original versions. Marty Stuart, teaming with the Staple Singers on the Band’s “The Weight,” proved to be no Levon Helm. Patti LaBelle, resorting to her usual histrionics in a duet with Willie Nelson on “Crazy,” is no Patsy Cline. Mickey Gilley, paired with Ben E. King on “Stand by Me,” is no Ben E. King. And so forth.

There was also so little chemistry between surprise guest Bob Dylan and Trisha Yearwood on a version of “Tomorrow Night” that you wondered if they had even been introduced.

Some moments, however, did work nicely.

Cole and McEntire were as playful and as comfortable as sorority sisters, drawing a standing ovation as they matched each other hot vocal lick for hot vocal lick on the old R&B; hit “Since I Don’t Have You.”

Yearwood, too, proved as effective a vocal partner for Aaron Neville on the Patsy Cline hit “I Fall to Pieces” as Linda Ronstadt has on their Grammy-winning efforts.

Sam Moore’s tribute to the late Conway Twitty, who teamed with him on the “Rhythm, Country & Blues” album, was one of the evening’s most tender moments. He sang “It’s Only Make Believe,” which was the country star’s first national hit.

More than those target moments, however, the real star of the evening was the concept itself. The program--which raised funds for the Country Music Foundation and the Rhythm & Blues Foundation--stands as a challenge to the industry to look for other ways to salute the musical traditions that serve as the foundation of contemporary pop.