WHAT'S HAPPENING : MUSIC.

Blues weekend: When Bay Area guitarist Luther Allison died recently, organizers of the 1997 Long Beach Blues Festival were left scrambling to find a replacement headliner for opening day of the popular Labor Day Weekend event.

There shouldn't be many complaints. Guitarist-singer Buddy Guy will handle Allison's slot at the 18th annual festival, which takes place Saturday through Monday on the athletic field of California State University, Long Beach.

The Saturday lineup features a host of Chicago artists, including Guy, harmonica greats Junior Wells and James Cotton, fiery guitarist Son Seals and blues-r&b crooner Otis Clay.

Delta bluesman John Lee Hooker headlines Sunday along with Memphis-born blues diva Koko Taylor, Chicago guitarist Otis Rush, Chicago singer-harpist Snooky Pryor and gospel group the Soul Stirrers.

Monday sees rock 'n' roll pioneer Chuck Berry close out the festival. Earlier, blues-r&b chanteuse Etta James, rock originator Bo Diddley, guitarist Ike Turner and guitarist-singer Joe Louis Walker are scheduled to take the stage.

Also Monday, the Chess All-Stars, featuring ex-Howlin' Wolf guitarist Hubert Sumlin, Chicago guitarist Jimmy Rogers, former Chuck Berry pianist Johnnie Johnson and singer-harmonica player Billy Boy Arnold, perform.

Cal State Long Beach is at 1250 Bellflower Blvd., Long Beach. Gates open each day at 9 a.m. and music starts at 11 a.m. Tickets are $25 each day or $60 for all three days. Free admission for kids 12 and under. Information: [phone].

?13- Fred Shuster

film

Sly move: Sylvester Stallone sheds his muscles and puts ``actor'' back on his resume to go mano a mano with Robert De Niro, no less, in ``Cop Land,'' an engaging melodrama about a town full of corrupt cops and the small-town sheriff who takes them on.

Stallone plays a wistful loser - deaf in one ear and, therefore, ineligible for the New York Police Department - who's been elected sheriff of ``Cop Land'' (fictional Garrison, N.J.) by its residents, lawless NYPD officers who figure they can run roughshod over the friendly oaf.

De Niro rides in as an internal affairs cop from across the river who needs Stallone's help if he's ever going to root out the corruption in the department. Will Freddy (Stallone) set aside his slavish admiration for the boys in blue to take a stand? Will the ghost of Rambo rise?

Will Freddy's collection of Bruce Springsteen records help him seduce the girl of his dreams (Annabella Sciorra)?

The plot gets a bit too thick in director James Mangold's story, but flavorful writing and full-tilt performances help make this tense but soulful drama one of the most entertaining movies of the summer.

?13- Amy Dawes

dining

Did summer end?: Some people must think that summer finishes at the end of August in Southern California.

St. Moritz, the restaurant located in the Toluca Lake Tennis Club at 6711 Forest Lawn Drive, Los Angeles, is going along with such thoughts by throwing ``a final summer bash'' Saturday evening.

There'll be a special menu and live piano music ``to roll out the summer in style.''

The menu lists a three-course prix-fixe dinner for $23.50 (children under 12 $12.50) that begins with a choice of chilled gazpacho or an arugula salad with toasted almonds and a raspberry vinaigrette.

The quartet of entree options are honey-dipped fried chicken with mashed potatoes, broiled porterhouse steak with barbecue sauce and mashed potatoes, blackened Cajun-style red snapper with pasta and a chardonnay sauce, and mahi-mahi with pasta and a teriyaki sauce.

Strawberry shortcake is the dessert with a coffee, tea or decaf option.

The restaurant's regular menu will also be available.

Reservations: [phone].

?13 - Larry Lipson

art

Modernist Mackintosh: No single term can adequately convey the prolific talents of Charles Rennie Mackintosh. Architect, painter, furniture maker, textile designer - the Glasgow artist did the lot, with a holistic approach that earned him the posthumous title of the ``European Frank Lloyd Wright.'' Like Wright, Mackintosh created entire architectural environments, right down to the furnishings and the flatware. Identified with the famous Glasgow style of the late 1890s, he bridged the erotic whimsy of art nouveau with the geometric austerity of modernism. In other words, he doesn't fit any prefab classification, which could explain why his work isn't better-known outside his native Scotland.

With luck, that won't be the case in Los Angeles this summer after the city gets a look at the large Mackintosh exhibition that just opened at the Los Angeles County Museum of Art. Composed of more than 250 works, the exhibition tracks Mackintosh's career from his working-class origins to his salad days as an architectural draftsman and the turn-of-the-century sunburst that saw the completion of his Glasgow School of Art, the remarkable Hill House and the unique tearooms he designed for Glasgow's trendy middle class. The exhibition also brings Mackintosh's wife and sometime collaborator, Margaret Macdonald, out of her husband's shadow.

Regular gallery hours are noon to 8 p.m. Monday, Tuesday and Thursday; noon to 9 p.m. Friday; 11 a.m. to 8 p.m. Saturday and Sunday. The gallery is closed on Wednesday. Call [phone].

?13- Reed Johnson

CAPTION(S):

3 Photos

Photo: (1) John Lee Hooker headlines Sunday at this weekend's Long Beach Blues Festival.

(2) Charles Rennie Mackintosh's designs took art nouveau and infused it with modernism.

(3) Sylvester Stallone is a small-town sheriff trying to deal with crooked NYPD officers in ``Cop Land.''