You might have wondered before a concert, with the musicians on stage producing a cacophony of sound: "Why are they making that racket?" The musicians are warming up, both themselves and their instruments. But by the time you see and hear them on stage, the more important warm-up period has already occurred, most often before they arrive at Powell Hall. Many musi- cians engage in their most extensive warm-up sessions before rehearsals, and save energy for the actual concerts.

But what is warming up really for? What are the goals? Are there indi- vidual routines? Playbill asked four St. Louis Symphony musicians what they do and why they do it, with a percussionist providing an alternative view.

EVA KOZMA, ASSISTANT PRINCIPAL SECOND VIOLI

"I normally do a very easy finger exercise that I made up many years ago - and I do it very slowly. Always do things slowly. When you first pick up an instrument, sometimes your hands can be so cold. You really need to relax and slowly start things. You need to go through all your fingers. If you start everything fast, you will hurt your muscles and joints.

"I have had to play 'cold' before, and it's not a good experience. The first few measures you're out of tune. You have a hard time going from one position to another. You feel yourself forcing more pressure into your body, and that's not good.

"Warming up is a lot about relaxation. Many times if I feel pressured or nervous I start playing on open strings, just with my right hand, the bow hand. If I'm very nervous I may actually shake, so I breathe; I relax the mus- cles in my elbows and hands. A teacher once told me that when you play a concerto, you keep your left hand in a relaxed manner, and just play by put- ting pressure on the strings with your bow and find the right tone. If you have relaxed one hand and create a more powerful sound with the other, I find it really helps."

ANN CHOOMACK, PICCOLO AND FLUTE

"In the morning I make sure I'm ready for work. I'll play after a shower so my body has warmed up. I play some chromatic scales right away, long tones, noodly things with my fingers. If I cover all the bases I know I'm good to go. If I don't do those things music-making is harder. I need to get my air moving, my fingers moving, my brain moving. I have a category of boxes to check off.

"Being warmed and flexible is to be ready for anything. If there is some- thing weird or with large leaps, I'll concentrate on that. If I saw some John Adams coming, for example, warming up would be about making sure my tonguing was in shape. I'd play a lot of _tudes."

KARIN BLIZNIK, PRINCIPAL TRUMPET

"I do free buzzing, like a bumble bee; flapping lips, like blowing a raspberry. I start with that buzz, then to playing mouthpiece, then to instrument.

"Like any part of any routine, I don't feel like working out, but I feel good after I do it. I never want to do breathing exercises. But when I do I feel pre- pared and ready to play.

"It's more about mentally getting myself centered. Some people can do the basics in front of a TV. I recently rented a studio, because there is not that much privacy at the hall and too many distractions at home. I take all the outside elements out so it's just trumpet, stand, and chair. It's good to have _tudes.

"I like to do _tudes early in the day until I'm slightly passed fatigue. That's when I stop playing. At the hall I do a lot of scale work and slurring, getting so my intonation response is immediate, especially in a piece like Sibelius 1, with those really soft entrances."

Kozma: "In general, I love to have Bach in my hands, a partita or sonata. I find it's good to play double stops. "I love to have an hour before rehearsal to focus on good sound and good intonation. I don't want to do this an hour before an actual concert. You don't want to play so much before the concert; you can lose your energy. This is true of wind players especially. They need to save their chops."

KozmaChoomack: "With wind instruments you don't want to tire your lips out. If I've played a lot of piccolo, I'll take my flute out and play. To warm up for pic- colo I'll play flute first. It's a more gentle entry into piccolo. Everything with piccolo is concentrated, the mouth is tighter. The flute is looser. It's good to spend more time warming on the flute before you get to piccolo."

KozmaBliznik: "I'm up around seven o'clock. In the shower I'm making sure I'm get- ting warm water on my lips. I use an electric toothbrush. No coffee because it makes me too jittery. I like to be at the hall 45 minutes to an hour before a show. The brass warm in the basement, the boiler room, mostly as a courtesy to the other players. If you need to play triple forte you need to warm that up. It gets loud in the boiler room. We'll often bring mutes on stage. I have a silent mute, so I can keep the feel of playing loud. "I don't give away melodies to the audience. You want them to be discovered."

THOMAS STUBBS, ASSOCIATE PRINCIPAL TIMPANI & PERCUSSION

Stubbs gives percussion demonstrations as part of the Symphony's Education program. He'll present a few exercises that he does routinely on the various percussion instruments, and tell the assembled schoolchildren "This is what I've been doing every day for more than fifty years."

So with that as background, it's not surprising to hear Stubbs say: "I don't warm up. I'm perpetually warmed up. You've got to understand that I've been playing for decades. When I was younger, I was practicing up to five hours a day. I still practice a lot every day, and I especially put the time into a new or particularly difficult part. But after all that, I'm ready to go."