FILMS, NOVELS and poetry start at one place, follow a consistent course to another and hopefully make a point somewhere along the way. Recorded pop music, however, has chronically suffered from a lack of thematic focus--the aural equivalent of short story collections, pop records often veer crazily from love song to drinking song to torch song to instrumental. As often as not, the only factor holding the individual works together--if, indeed, anything does at all--is stylistic, the musical presence of the performer. An overriding theme must, of necessity, go by the boards; the constraints of the medium make it impossible to Make A Statement in ten or twelve unrelated songs.

The answer to this problem has been the concept album, and it's proven largely unsuccessful. The idea of doing an album comprised of musical reflections on one central idea is a noble one; but all too often, the listener is bludgeoned with the artist's self-proclaimed sensitivity, the connections are strained, and the themes themselves are pretentious or trivial. In the rare instances where concept albums have succeeded (Randy Newman's Good Ole Boys, for example), the songs have seemed like elements of a large orchestral work; the whole has seemed greater than the sum of its parts. Such records are the exception, though. Concept albums generally fail to do the very thing they set out to do, and they emerge fragmented, insignificant failures.

JACKSON BROWNE may well be the prototypical Southern California rock and roll star. Like the rest of the L.A. pop crowd, he's known for squeaky-clean vocals, introspection run rampant, a reliance on the studio pit crew of J.D. Souther, and Eagles Don Henley, Glenn Frey et al, and an obsession with The Road. The latter has been the dominant image in his music since his second album, both as a metaphor for change and a literal determinant of modern life. "Take It Easy" and "The Road and the Sky," from his second and third albums respectively, were two early road songs. In Running on Empty, his fifth and latest release, Browne presents his most extensive look yet at The Road; the album was recorded live on tour last summer, and the material deals exclusively with the traveling life of the pop star. As a concept album, it's a real triumph; as a Jackson Browne album, however, it's a dismal flop.

Running on Empty represents the concept album taken a step further--its thematic unity is bolstered by some imaginative production work. One of the cuts, for example, Danny O'Keefe's "The Road," begins in Browne's hotel room, played by a skeleton crew of two or three pieces. During a pause between the second and third choruses, crickets can be heard in the background; when the song resumes, it's the full band playing it on stage a week later. The effect of splicing the two performances together may seem overly cute, but the result is surprisingly moving. In all, about half the tracks were recorded on stage. The other half consists of performances in hotel rooms, backstage rehearsal rooms, even aboard the band's tour bus. The idea of capturing live performances other than the ones on stage is brilliant, and goes a long way toward giving the listener a more complete picture of life on the road than the traditional "live" album.

MUSICALLY, TOO, it's the off-stage performances that are the best. Browne and Frey do a delightfully drugged-out version of Rev. Gary Davis's "Cocaine," recorded at a Holiday Inn in Edwardsville, Illinois; and Russ Kunkel stars on a makeshift drum kit on "Nothing But Time," a funky traveling song done on the band's Continental Silver Eagle bus "somewhere in New Jersey," the liner notes tell us.

With a couple of exceptions, the album falls apart in the on-stage performances. The exceptions are the title track, which opens the album and is very good indeed--a song about growing up and changing, and the physical and spiritual traveling one has to do along the way--and the record's closer, a remake of the Zodiacs' mid-1960s hit, "Stay." In between, the songs are disappointing. "The Load-Out," a tribute to Browne's roadies, is nothing less than spectacularly dumb. Lyrically inane as well as musically torpid, the song includes such unbearably bad lines as:

... haul them trusses up and get 'em up them ramps,

'cause when it comes to moving me,

you know you guys are the champs...

From the man who wrote "The Late Show" and "My Opening Farewell,' tripe like this is awfully sad to hear. "Love Need a Heart," a Lowell George composition, is an endless dirge indistinguishable from any nine Linda Ronstadt songs. "You Love the Thunder" is a faceless, mindless rocker in the mold of "Redneck Friend," but lacking the wit. It's a humorless song--and without a sense of humor, upbeat L.A. rock can be terribly dull.

THE PROBLEM with Running on Empty stems from the almost uniformly bad original material. The clear-cut progression that Browne's writing showed on his four previous albums appears to have ended with The Pretender; he seems here to have attempted the definitive concept album at the expense of cutting a good Jackson Browne album. He doesn't do anything new on this record, and he doesn't re-do the old especially well. What makes this album especially noteworthy is, quite simply, its gimmick. It's the most comprehensive and sympathetic portrayal of life on the road that a rocker has produced to date; and the idea meshes well with the production techniques used to bring it to life. Running On Empty is one of those rare records that vindicates the idea of the concept album. Unfortunately, anybody out of L.A. could have made it. Browne's uniqueness, at least for the purposes of his latest release, appears to have been lost somewhere on the road.