Movie soundtracks, like other kinds of functional music, tend to vary in terms of what they accomplish. They can act merely as mood-inducing backdrops for different scenes or help to stylize the overall production. Sometimes they display a personality that succeeds independently of the movie itself, but this is quite rare. Three current soundtracks, "Chariots of Fire," "Ragtime" and "Pennies From Heaven," attempt to achieve these ends, with "Pennies" enjoying the most success.

Vangelis' score for "Chariots of Fire" is an example of the backdrop school. Similar to Giorgio Moroder's score for "Midnight Express" in its ambition and reliance on synthesizer as major instrument, it never reaches the powerful emotional depth of Moroder's work. There is, in fact, a restraint in these eerily pretty pieces that borders on the reclusive.

While Vangelis is to be admired for his efforts to get across musically such ideas as physical endurance and mental control -- concepts that actors themselves find challenging to simulate -- he has too often compromised his musical resources for the sake of plotline. The result parallels his reluctance to wield the power of music: The track is often pretty in a sullen, sterile way, but never exactly beautiful.

"Titles," the opening cut, is the most indicative of this dilemma. Here Vangelis successfully evokes the loneliness of human endeavor with a spare, simple keyboard movement set against wispy, echoing percussive effects. It is pleasant enough to have earned airplay, but it seems incapable or even wary of resolution, and the result is a lengthy buildup with no denouement. One is hard put to tell whether the track owes its appeal to the music or to the sustained popularity of the movie itself.

The evidence that problematical restraint was not solely Vangelis' doing becomes clear on "Jerusalem," performed by the Ambrosian Singers. By its very nature a rousing anthem with great potential for soul- stirring, the song is executed here with an alarming lack of depth or conviction, and this raises the possibility that the project as a whole was approached with a calculated detachment by all the principals.

Detachment is not a problem with the soundtrack of "Pennies From Heaven." Whatever fault one may find with the motives of the movie-makers, the loving care with which these songs were mined and re- introduced is not to be questioned. Certainly this collection of very American standards was meant to evoke a slice of Depression-era life, and this it does. But it also summons nostalgia even for those with no memory of those times.

Listening to these tracks, one is astonished to rediscover the power of one generation's cultural contribution. If you were born well after these songs had their day, yet you find yourself singing along with Conrad and Friend's "Yes, Yes!" or Cole Porter's "Let's Misbehave," consider it evidence of popular music's awesome ability to penetrate the barriers between decades.

Like the black-and-white photographs that visually symbolize the Depression, these standards are a bittersweet aural panorama that expose the changelessness of the human race, as well as its great capacity for change. Hearing Rudy Vallee and His Connecticut Yankees perform "Roll Along Prairie Moon," with its strangely effeminate harmonies, I'm reminded of how popular musicians were once relegated to the nether rungs of the social ladder. But listening to Dolly Dawn's gloriously phrased, sadly wrought "It's a Sin to Tell a Lie," I'm reminded of nights in my own childhood when the distinct enunciation and angelic soulfulness of Bernadette Peters' voice on Johnny Carson's show would draw me padding down the hallway to my parents' bedroom.

Nostalgia is also a goal of Randy Newman's soundtrack for "Ragtime," though he is far too complex a character for such a simple ambition. What an unforgivable shame to have exploited one of America's greatest composers for a project so calculated and simple-minded!

From the opening track, it's obvious that too many cooks conspired to spoil this bland and skimpy broth; these are not songs, but snippets and reprises thrown together. Since when did Randy Newman, whose own family background includes a noted soundtrack composer, need a music consultant (Gilbert Marouani), an orchestrator (Jack Hayes) and a host of other helpmates to do what he does naturally by himself?

Newman has always been able to tug a nostalgic heartstring. Previous works such as "Louisiana 1927" and "A Wedding in Cherokee County" made me long for the grotesquely enchanting South of my childhood -- a neat trick, considering how I despised the place. "Ragtime" should brim with such this kind of sentimental sleight- of-hand so unique to Newman. Instead, it misses entirely his wry combination of irony and heart, and the only place Newman is really identifiable is on "Sarah's Responsibility."

Newman's respected name and easy ability to portray American life through his compositions were clearly considerations for having him write the "Ragtime" score, yet he was obviously not given the autonomy to assert his personality. If you want to hear what "Ragtime" could and should have sounded like, listen to "Sigmund Freud's Impersonation of Albert Einstein in America," from 1977's "Little Criminals." It was originally intended for the movie score, and playing it against "Ragtime" tells a disappointing tale indeed.

THE SOUNDTRACKS -- "Chariots of Fire," Polydor PD-1-6335. "Pennies From Heaven," Warner 2HW 3639. "Ragtime," Elektra 5E-565.