You could hardly imagine a better project for director Walter Hill than "Crossroads," a movie that's about music, that returns him to the scrabbly flatness of the South, and that delves into what's mystical and gothic there. So when the movie turns out drab and predictable, it's depressing -- you think Hill has become a stranger to his own sensibility.

By day, Willie (Ralph Macchio) studies classical guitar at Juilliard; by night, he dreams of being a blues man, poring over histories, mimicking licks from his Robert Johnson records. He finds Blind Dog (Joe Seneca), Johnson's harmonica player, imprisoned in a low-security nursing home (years ago he killed a man), and together, they take it on the lam -- Willie in search of Johnson's long-lost 30th song, and Blind Dog in search of that Mississippi crossroads where, years ago, he traded his soul to the devil for the secret of singing the blues.

Seneca makes Blind Dog a lovable grumbler with exquisite comic timing -- he grumbles to a beat. You see what's generously human about him, but you also see what's not quite human in his past; the Faustian bargain is evident in glimpses, when Seneca is inward, faraway. The old harp player's prickly pride in the blues man's code is at once funny and poignant, and it should open up the relationship with the boy, as the code is passed on.

But while the code is passed on, little else is. Macchio is too self-involved, too captivated by his own rhythms. In "The Karate Kid," Pat Morita was the perfect foil for him -- cryptic and out of it, he simply seemed to be ignoring Macchio. The kid rebounded off the older man's impassivity. But here, there's no frisson when Macchio and Seneca don't interact. Macchio just seems snotty.

With this kind of inertia in the central relationship, the movie is lost. Screen writer John Fusco has penned the dreariest kind of road movie, a series of events that don't go anywhere and don't link up with each other. At each turn of the road, Willie is supposed to learn something about life -- it's like reading some dull 18th-century book of advice. A girl is introduced (Jami Gertz, the Prisoner of Pout), for example, so that Willie can have his heart broken. Then, you see, he can really play the blues.

The real reason for the girl, of course, is to make "Crossroads" accessible to a teen audience, no surprise in a movie that is compromised at every turn. The movie has no edge, no real jeopardy -- you know there's going to be a happy ending because happy endings are what kids like these days. "Crossroads' " cinematography (by John Bailey) is dense, almost chocolatey, the music (by Ry Cooder) entertainingly twangy, but neither accumulates -- there's no one there to put them together. It is beginning to seem as if the worst thing that ever happened to Walter Hill was the success of "48 Hrs." -- his new movie tells you almost nothing about the blues, but much about the gold.

Crossroads, at area theaters, is rated R and contains profanity and sexual situations.