ARIA - An anthology of minimovies, all of them vaguely inspired by passages from operas. There's a surprising amount of sex, as if nude bodies were the first thing anyone thought of while listening to Verdi or Wagner. The directors include such imaginative types as Robert Altman, Nicolas Roeg, and the inevitable Ken Russell, who practically invented this kind of filmmaking. Derek Jarman's offering is lovely, and Jean-Luc Godard's has its moments. Otherwise the quality level is generally low. (Not rated) THE BEAT - A seemingly backward teen-ager opens the eyes of his high school friends to new and offbeat possibilities in life. Written and directed by Paul Mones, who captures the raunchy cadences of inner-city slang and elicits a couple of notable performances, including one by John Savage as a canny schoolteacher. The movie is too ragged to realize its best possibilities, though. (Rated R) LOVE IS A DOG FROM HELL - Three episodes in the life of a man named Harry, carrying him from boyhood to adulthood and focusing on his need for love, which is never satisfied. You can tell the picture is based on Charles Bukowski stories, because it's full of aimless boozing, sexual obsession, and incredibly bad taste. Against all odds, though, Belgian filmmaker Dominique Deruddere injects a significant measure of caring and compassion into his material. (Not rated) SOUTH OF RENO - Drama about an oddly likable loser caught between his unfaithful wife and her belligerent lover. The opening moments are promising and a few later scenes are engagingly offbeat, but the performances are klutzy and the screenplay is extremely uneven. Directed by Mark Rezyka from a screenplay he wrote with T.L. Lankford. (Rated R) THE STEAMROLLER AND THE VIOLIN - The brilliant Soviet filmmaker Andrei Tarkovsky directed this ``diploma film'' at the Moscow Film Institute in 1960. It's an appealing little reverie about a musically minded child who strikes up a friendship with a road worker. The story is slight, but the colors are wonderfully delicate, and Tarkovsky shows a strong instinct for in-depth visual composition that prefigures the sophistication of his later work. Andrei Mikhalkov-Konchalovsky, another MFI filmmaker who would have a bright future, co-wrote the screenplay (Not rated) WHAT'S OPERA, DOC? - Reissue of the classic Warner Bros. cartoon, wherein Elmer Fudd hunts Bugs Bunny to Wagnerian strains. Directed by Chuck Jones. (Not rated) WILLOW - In a legendary time and place, a band of little people sets out to return a magical baby to the land where she belongs, so she can fulfill her destiny as successor to a wicked queen. They have more adventures than you could shake a magic wand at. Directed by Ron Howard from a story by George Lucas; the filmmakers strain so hard to be mystical and fey that the picture seems more labored than it should. The performances have a lot of energy, though, and it's nice that a new generation of filmmakers is willing to recycle the old myths for a new generation of moviegoers. (Rated PG) RATINGS: Films with ratings other than G may contain varying degrees of vulgar language, nudity, sex, and violence.