"And now the king of country music, Ray Acuff."

Which is, of course, why they have rehearsals. Though Acuff's real name, Roy, follows quickly, the incident draws a bead of sweat from veteran television producer Gary Smith, sitting in Constitution Hall only hours before the black-tie gala celebrating the Country Music Association's silver anniversary.

Smith is the general. The 40 stars who will appear in a two-hour program are his battle troops.

"But I don't order anybody around," he adds quickly.

The support troops include sound, light, camera and cue-card crews, caterers, security staff, publicists. There seems to be plenty of everything except what they really need: time.

"Anytime that you do a show of this size, with retrospective pieces where you're dealing with many of the old-time performers, there's a tremendous logistic problem," says Smith, who also does the Emmy Awards. Despite six months of planning, "it's a question of talent coordination, getting people in town in time to rehearse . . . and these are people who are not necessarily waiting around just to do your television show. Sometimes you get people at the last minute. You get here and you have three days to put everything together. We do have a final script--as of about 10 minutes ago."

Just hours before show time, a remarkably calm Smith sits in the hall, eyes darting from script to monitor screen to stage. The normally staid hall bustles with preparations: technicians and country music stars stepping gingerly around each other, eight cameras finding their range and focus, sound levels being set for the 30-piece orchestra, stage movements being blocked out, scripts and musical segments being rewritten and rehearsed. It is the third day of run-throughs, the last before a dress rehearsal that is to come only hours before the actual taping for CBS (the program will be shown April 13).

With 40 country stars and their families, friends, bands and support troops drifting around, rehearsals tend to be a little work and a whole lot of waiting. Constitution Hall has begun to resemble a train station during a strike.

The two ends of the halls are transformed into couch-laden hospitality centers. In one, Charley Pride hunkers down for a little shut-eye--he's been there since 9 o'clock--while Bill Monroe, the father of bluegrass, sits nearby greeting old friends.

Ricky Skaggs, country's newest star, does a little picking with Merle Travis (Travis-picking, no doubt). Skaggs seems genuinely thrilled about meeting Gene Autry and former Louisiana governor Jimmie Davis (who wrote "You Are My Sunshine"), but he seems most pleased uncorking a few guitar runs with whoever stops by. That may be the legacy of his bluegrass background and countless parking lot picking parties. Makes it easy to find him, though. When someone asks the drummer from Alabama where Skaggs might be, the reply is assured: "He's in the Green Room picking guitar."

At the other end of the hall, Barbara Mandrell cuddles 6-month-old Elizabeth Walker, even gets a good burp out of her. Elizabeth looks right at home with her celebrity nanny, but she may be used to it by now: Her father is Bill Walker, the show's musical director and a Nashville studio vet. Her mother, Jeanine, sings in the backup vocal group. "She's got to get used to show business," Walker says, matter-of-fact proud. Elizabeth does not object.

Constitution Hall has been remade into a gigantic television studio, with massive banks of overhead lights and a huge set that extends over the first row of seats.

On stage, Campbell, Gatlin, Murray and Mandrell are getting down to serious business. That's not a law firm, but the sudden alliance of Glen, Larry, Anne and Barbara, who among them have more than a few television specials under the belt. They're doing a medley of No. 1 country songs and discovering the contours of one another's voices, harmonies worked out by a thrust of the hand up or down. Also, Gatlin and Campbell are doing a little clowning, like high school boys at the school pageant.

At the end of the medley, Murray says, "That's about as close to perfect as we're ever going to get," but Campbell quickly interjects, "We don't want that, they'll want it that way every time." Light laughter ripples through the onlookers, who know better.

Ray Charles and Ronnie Milsap, both blind, are led to the stage and work with braille scripts. As they settle into a medley of Don Gibson classics, John Schneider jumps up to the edge of the stage as if it were the General Lee (his car in television's "The Dukes of Hazzard") and clicks away with a camera.

Mooney Lynn, Loretta's husband, sticks to the front of the stage for his photo opportunities. He's got on his trademark cowboy hat, a green satin touring jacket and a gaudy Mooney belt buckle occasionally visible under the large Mooney belly. Stars are fans and fans are stars today and everyone seems comfortable with one another; they applaud each other in rehearsal, trade war stories in the foxholes.

Milsap and Charles make a few jokes about their blindness ("Ray, you are there?") and that they won't be relying on cue cards, but in the back of the hall, Keith McNulty and his crew from California's Ad Libs are busy scrawling out changes in the script with thick felt pens on huge white cardboard placards.

The middle entrance to the hall is clogged with segments, starting with Minnie Pearl's intro ("MINNIE: HOW-DEE! AUDIENCE: HOW-DEE!").

"We're rewriting up to and sometimes during show time," says McNulty. "Sometimes while we're flipping some cards, we'll be back here printing other ones."

Behind him sits a card bearing the word "Beautiful."

On stage, Acuff (Roy) is introducing a little segment on Jimmy Rodgers. He stumbles a bit and ad-libs a bit. "Let me get used to your turning and you get used to my slowness," he suggests politely.

Gary Smith prods Acuff gently. "Roy, we've got to move that speech along."

Acuff comes out for a bluegrass segment. He'll play fiddle behind Skaggs, Monroe, Grandpa Jones and West Virginia Sen. Robert Byrd. Another politician, Jimmie Davis, reads the introduction cue card against a distracting buzz.

"And now for that special noise that we listen to . . . that special sound we listen to called bluegrass . . ."

That's why they have rehearsals.