At 4:32 p.m., a scant two minutes past the appointed rehearsal hour, Sir Georg Solti walks briskly to center stage. Dressed in tan polo shirt and navy slacks, he drapes an extra sweater over the back of a nearby chair, picks up his baton, and promptly raises both arms. The response of the waiting Chicago Symphony Orchestra and Chorus is immediate. The final rehearsal of the next night's performance of Haydn's ''The Creation'' is under way.;
Hungarian-born Sir Georg, music director of the Chicago Symphony for the last 12 years and the man generally credited with restoring it to what many consider one of the greatest orchestras in the United States, if not in the world, gives a spellbinding visual performance of his own as he reaches for the particular musical interpretation he wants.
His arms and the rest of his body from head to toe are a picture of almost constant motion. Now crouching, he rocks from one leg to another. He slices the air in a karate chop with his left arm during a particularly rhythmic passage for violins while raising only a few fingers of his right hand to get the fuller volume he wants from the woodwinds.
Solti is after perfection - the bright, clean, sweet sound for which this orchestra is famous - and his concentration is total. Occasionally his husky voice can be heard quietly issuing terse instructions: ''More flute . . . less cello . . . no attack.'' At one point he turns to longtime chorus director Margaret Hillis for approval of his vocal conducting. She is sitting fifth row center in a blue pantsuit in the largely empty auditorium: ''OK?'' ''OK.''
Through it all, the music never stops. As one player later explains, ''He trusts us to do it the way he wants next time.'' Says general manager John S. Edwards, who recruited Solti for this post in 1969, ''He gives them the feeling he's confident they'll catch on and correct 90 percent of anything wrong themselves.''
Suddenly, after plucking the air to get a more staccato sound from a chorus of ''hallelujahs,'' Sir Georg announces with a sweep of his left arm that it is intermission time. As if to confirm that anyone looking on has witnessed not only a musical but a strenuous athletic event, the conductor throws a white towel around his neck as he chats with a few of the musicians and exits left.
Though the Solti stamp on this orchestra is undeniable, he would be the first to admit that it takes more than a strong conductor to make a great orchestra. He frequently speaks of the 106-member team as a ''jewel'' and of his relationship with it as a ''very happy marriage.''
''I have never found a group of musicians who take music so seriously,'' he says. ''They are wonderfully quick if they respect you and if you are precise in indicating what you want. . . . I'm a very organized fellow, and I know what I want. I'm not improvising.''
''The greater the orchestra, the more flexible it is'' in adjusting to the demands of different conductors, says Leonard Slatkin, who recently guest-conducted the Chicago Symphony in a Beethoven, Mozart, and Shostakovich program. ''This orchestra is so fast. You say something once about the kind of sound you're looking for, and you've got it.''
Even the orchestra's most veteran members still spend hours practicing each day to keep up their skills.
''Being familiar with all the music is not the same as practicing,'' insists Donald Peck, who holds the orchestra's principal flute position and is a frequent soloist. '' 'Woodshedding' - playing long tones and scales - gives you control. If you only play with the orchestra, those things get rusty.''
''Playing with other people is the hardest thing,'' notes Paul Phillips Jr., one of the tutti, or mainstay, players in the violin section. ''You have to really put your solo capabilities away and try to blend with everyone.'' Phillips joined the orchestra last year. ''But it's very important, especially with stringed instruments, to play your scales and etudes by yourself so you can hear what you're playing. I try to practice a couple of hours a day - it catches up with you eventually if you don't.''
Keeping the orchestra members playing, planning and scheduling the concerts, selling seats, raising funds, and tending to all the backstage logistics from microphone to lighting levels is currently a $15 million-a-year business proposition.
Making it all work requires a large staff and plenty of dedicated volunteers to put in time behind the scenes. And even then things do not always go as smoothly as they may look to the audience. Just ask stage manager William Hogan. He files a standard request for a 73 degree F. temperature level and overhead theatrical lighting wherever the orchestra goes on tour, and makes a point of arriving at any hall a good four hours before the concert.
He accompanied the orchestra on its highly successful European tour last summer, and will head out again with the orchestra in January on another major tour of several Midwest and Western cities.
Usually, Mr. Hogan says, the musicians must make do with whatever conditions and equipment the concert hall in question happens to have. In the case of their performance at La Scala in Milan, that meant they had to play under cable-hung pan lights (''the sides of the violinists' faces were black''), while in downstate Illinois school gymnasiums, the musicians sometimes have to play a little louder to compete with the hum of mercury vapor lights.
When the Chicago Symphony travels anywhere, a full 32,000 pounds of clothes, instruments, and other gear goes along with it. Often the baggage is flown in well ahead of the players. But Mr. Hogan and every member of the orchestra remembers vividly the day in London on their recent tour when fog and customs formalities at the airport held up the freight and forced a 15-minute delay in the starting hour. But the audience in Royal Albert Hall did not seem to mind. Indeed, on hearing of the delay, one ticket holder in the standing section yelled back: ''We've waited three years to hear this orchestra - we can certainly wait another 15 minutes.''
And the wait was brief compared with the time recalled by general manager Edwards. When he was managing the St. Louis Symphony, that orchestra arrived at one stop a full two hours late for a performance because of icy railroad tracks. Not only was most of the audience still waiting at 10:30 when the players arrived in their traveling clothes (''that's a sight in itself,'' Mr. Edwards says), but they kept the musicians on for five encores. The concert broke up at 1 a.m.
Being in the symphony business requires a willingness to make compromises and to be ''infinitely flexible,'' he says. ''And after you've been in it for a while, that's not as hard as it sounds.''
But those responsible for performance details insist there is always a current of management concern running before and during any concert. And there are times, they say, when a concert has to be canceled - such as during Chicago's blizzard of 1979, when key players in the suburbs were unable to dig their way out.
''You're always worrying,'' declares orchestra manager Paul Chummers, the ''detail'' man. He is already working on the 1984-85 concert schedule. ''You think you've got everything down to a system that's infallible, but there's a constant concern that something could still go wrong.''
Support from citizens both as concertgoers and dollar-givers is a critical ingredient of the Chicago Symphony's success. The annual spring radio marathon, which has replaced the traditional symphony ball, raises more money - $525,000 last time - than any of its counterparts in any other city. Selling premiums for everything from chats with Maestro Solti to a cruise for two, the orchestra's Women's Association has raised $2 million during the Marathon's six-year history.
''In sheer dollar volume, this is the most supportive orchestra community in the world,'' Mr. Edwards confirms.
Fund raising and income from a $20 million endowment account for about one-third of the budget, while the remaining $9.5 million stems from income earned through ticket sales, recordings, domestic tours, and radio and TV appearances.
One of the orchestra's chief assets is its 76-year-old auditorium headquarters, which has just undergone a $3 million-plus renovation that started with the gift of a pipe organ and went on to include major remodeling and a repainting job. Over the years such distinguished composers as Ravel, Bartok, and Hindemith have presented their music here. Since the orchestra's travels abroad can be a sensitive subject with Chicago donors who often prefer to encourage more hometown appearances, the recent European tour was financed under a separate $1.5 million budget. Its source: concert fees, corporate donations, and a $500,000 joint contribution from the city and state, both eager to draw more tourist and convention business here. All four European tours over the last decade, for instance, have included a stop in Brussels, where Illinois maintains a trade and development office. The music, Mr. Edwards says, is not incidental but is sometimes sandwiched carefully in between courting parties. Not surprisingly, the general manager is a staunch defender of such tours as a necessity rather than an extravagance. Each tour, he contends, has raised donations to a new plateau. As one orchestra member puts it: ''People like to contribute to a winner.''
At an informal sit-down session with Marathon givers who have paid $10 each for the privilege of a conversation with the maestro, Sir Georg, carrying his peripatetic thermos of lukewarm tea and gesturing as expressively with his arms when he talks as when he conducts, offers donors a loaded answer when they ask about plans for future tours:
''We always have plans to go everywhere,'' he says, his deep-set brown eyes flashing with a mischievous twinkle. ''This jewel should be known outside Chicago. What we need are the same three things Napoleon said he needed for his wars: money, money, money.''
For the most part, Chicagoans keep Orchestra Hall well filled for the September-to-June season. This year a record 12,000 bought season tickets. As Solti sees it, he knows he and the orchestra are fully appreciated, but he wishes audiences here would make a stronger effort to stifle coughing and other interruptions.
''You must help me - I can't do it alone,'' he says. ''I know everyone listens to us with the greatest possible joy and love - I get hundreds of signs of it every day. But we need some more outside demonstration of it. There's no excuse for bad behavior. You can't play if people don't listen.''
Indeed, as he tells it, the most memorable moment of the recent tour was the at-first silent standing ovation given the orchestra by an Amsterdam audience after the subdued ending of Mahler's Ninth Symphony.
''I will always cherish that moment - it was the most moving I can remember in my entire musical life,'' he says.
Orchestra members, interviewed in their basement locker room under the stage, a frequent site for small group rehearsing and intermission bridge and poker games, generally give music director Solti high marks for his efficiency, demanding professionalism, and no-insult civility.
''He's very professional, avoids personalities, and there is no other conductor that can compare with him for sheer efficiency of rehearsal time,'' says Donald Koss, a former high school math teacher who has been the orchestra's timpanist for 19 years. (''Some people still consider me a rookie,'' he remarks.)
Most orchestra members agree that a conductor can make an enormous difference in interpretation and the sound produced. Some can instantly recognize orchestras and individual players just by listening.''
Every conductor makes a difference in the tone produced, especially if he's good,'' flutist Donald Peck notes. ''The Philadelphia Orchestra, for instance, had a particularly lush string sound when (Eugene) Ormandy was conducting there. He's coming here, and I expect that within an hour, without his saying a word, we'll be sounding like the Philadelphia.''
Mr. Peck says an orchestra often responds in sound and mood to what members see visually: ''If the conductor is tight, we tighten up. . . . If he's flowing, we respond. . . .'' The chief flutist joined the orchestra 24 years ago when dictatorial conductors were more common and Fritz Reiner was wielding the baton. ''The music director didn't really have to get along with the orchestra in those days,'' Mr. Peck says. That concept began to change, he says, under Reiner's successor, Jean Martinon, basically a gentle man ''caught in the middle.'' Mr. Peck describes Solti as similarly demanding but more ''gentlemanly.'' If he disagrees with a musician's interpretation of a solo passage, for instance, Mr. Solti may say, ''That's beautiful but I prefer . . . .''
Solti, who began his musical studies as a pianist, once studied conducting in Salzburg under Toscanini. He credits his mentor with teaching him the value of persistence but says that Toscanini was like a ''spoiled child'' in his lack of tolerance for any mistake. ''He saw each one as a personal insult - not against him, but against the composer,'' Mr. Solti says.
The Chicago Symphony and its current director often get rave reviews when assessed by East Coast and European critics - one Vienna paper termed them ''the aristocrats of Lake Michigan,'' and Salzburg ''one sensation richer'' for their performance.
But critics closer to home are sometimes less generous. The Solti solution is simple. He relies on precensorship.
''When they bring a review to me, I know it's good,'' he says. ''You can't live with bad reviews. I don't read them.''
Chicago newspapers and some symphony subscribers have occasionally criticized the music director for spending what they see as too little time with the orchestra. This year Mr. Solti, who lives in London with his wife, Valerie, and two daughters and also serves as conductor of the London Philharmonic, will conduct the Chicagoans for about 12 weeks of its subscription season. Some years the total is closer to eight or nine weeks. In Solti's view, it is the quality rather than the length of time which makes the critical difference. Generally, the musicians and management agree. ''I think it's healthy for an orchestra to work with a lot of good conductors, and there aren't enough to go around,'' Mr. Koss says.
Mr. Solti also comes under fire from local critics for not including more modern, particularly American, composers and premieres in his programs. He is considered particularly partial to Mahler, Bruckner, and Wagner and, in fact, is leaving his London post at the end of this season to record Wagner's complete ''Der Ring des Nibelungen'' at the Bayreuth Festival in Germany over the next three summers.
Solti bristles under such criticism of his repertoire and last year even held a press conference to challenge it. He argued that the orchestra plays more American and more new works than most of the world's other orchestras. By Edwards's count, the Chicago Symphony as of three years ago had played 168 works by composers born in the 20th century. Apart from that, Mr. Solti suggests it is appropriate for younger, less established conductors to do more experimenting with new scores. He prefers for reasons of quality to do what he knows he does best. Orchestra musicians tend to agree and say they think it is the critics rather than the audiences that want more varied programming.
''This orchestra has a huge range, and I don't think anyone's upset that we don't do more contemporary work,'' Donald Koss says. ''Some modern music is just an assault on the ears.''
Programming is not necessarily an easy chore. When guest conductors submit their choices, the staff has to check them against a ''clash'' list to be sure the orchestra has not played the pieces recently and has no plans in the near future to record them. Another consideration when the orchestra goes on tour is that no audience feels short-changed. The annual concert season includes 10 round trips by private train to Milwaukee. Never, according to Mr. Chummers, would an all-Mozart or Haydn program requiring a smaller-than-usual orchestra be put on the schedule.
''A lot of people wouldn't feel they'd been to the symphony unless they've seen 106 players,'' he explains. ''If only 75 to 80 people were on stage for the whole evening you'd hear a lot of griping about 'Where was the rest of the orchestra?' ''
Musicians concede that playing in an orchestra is a job like any other with some routine - rehearsals are called ''drudgery'' by some. But most admit also to a certain continuing thrill in performing as a team before a live audience.
''The greatest thing about being a musician is that this is a living art,'' says Koss, who often visibly carries the beat of the music in his whole body as he plays the kettle drums. ''Each time we do a Bruckner or Mahler, it's always different. . . . We're all music lovers or we wouldn't be here. It's a great job.''
''Often there's a collective feeling in the orchestra,'' Donald Peck adds. ''Some nights you go on stage and you just know it's going to be a great concert - you're inspired.''
About half of the musicians in the Chicago Symphony have come through the ranks of the Chicago Civic Orchestra, an official training body and a rarity among big-city orchestras. Nationally, the Chicago ranks as third oldest in the country (behind Boston and the New York Philharmonic), and its management is already planning to celebrate its centennial in 1990. Mr. Solti, whose contract is assured of renewal next year, says he has every intention of being part of the festivities.