Bob Batchelor was 36 before he realized every child's dream: drumming away and joining the circus.

Seven years later, he has missed only five performances with the Ringling Brothers and Barnum & Bailey Circus. Is that remarkable? Consider, please, the following: there are two shows a day, three on Saturday; each show runs about three hours; the drummer never, ever stops working. "I play pretty much from the time the whistle blows to when it quits," Batchelor says. "It's a big job."

That job is to underline the "tricks" that the circus performers are doing, to punctuate the whole show. That means being snappy for the clowns, tremulous for the acrobats, heroic for the parades, dramatic for the high-wire acts. The circus orchestra numbers 15, but it's Batchelor sitting behind his seven-piece kit, pushing out rolls and rim shots, who seems inextricably tied to the action out front.

"We do 500 shows a year but no two of those shows are the same," he says. "With acts of the caliber that we have, people are out there literally laying their lives on the line every day. The two main things I'm thinking about are the tricks and time. I'm watching what's going on in all three rings. Of course, as time goes by, you learn the acts and know when to expect certain tricks. But it never seems to go exactly the same; some of the tricks are so difficult, particularly working with the animals--they're so unpredictable."

Batchelor has a particularly close rapport with the most difficult act he has to support, the Carillo Brothers, who work on a high-wire 30 feet above the ground--with no net. "I'm the only thing that's going on--the drums and the guys up there on the wire. The tricks that they're doing are very difficult, so we can't repeat things the same every show. It's a matter of really watching close and trying to stay with them. Often they have to improvise if the trick doesn't go exactly the way they want to; occasionally they slip and have to grab a wire, come up and try again. I try to keep it interesting, but I always emphasize what they're doing. That's what people paid their money to come see--people risking their lives."

Batchelor, 43, is a native of Greensboro, N.C., and a graduate of East Carolina University, where he played in bands with Keith Green, now musical director of the circus orchestra. Green, who doubles on Maynard Ferguson-style trumpet, had joined the circus several years earlier and when he asked Batchelor to join him, "I felt it was going to be a challenge because it was totally different from anything I'd ever done."

The circus "will never use taped music," Batchelor says. "Every building is different, the size of the track and arena has an effect on the tempos and the placement of props. It's just a wing-it sort of proposition." The permanent traveling band includes bassist David Gannett, keyboard player Dave King and trumpet player Bob Martin. Ten local musicians are hired at each stopover, given an hour's rehearsal to acquaint them with transitions and difficult tempos, and then it's on with the show. The newcomers tend to be good sight readers; the starting five, so to speak, know the music inside out and work strictly with visual cues; as a result, there tends to be a lot of the good-humored camaraderie that marks circus life.

There are also many serious considerations, including the band's volume. "I don't know whether or not it bothers the animals, but it bothers Gunther Gebel-Williams when the band is too loud," Batchelor says. "That's because the cats can't hear his commands. I think the animals themselves are accustomed to the noise because they're always around this environment but you have to be careful that the music doesn't get so loud they can't hear the commands. If they can't, Gunther might be in trouble. We watch all the animal acts closely; they'll wave their hands, give us a visual cue if it's too loud."

Batchelor and the regular musicians can also spot when an act is in trouble. "I know what they're supposed to be doing and if they're not, something is wrong. If it's an animal act, maybe the animals are a little balky that day, or they don't feel like working. Animals are unpredictable no matter how well they're trained. In those situations, you're always alert to see what's going to happen next."

And in case of an accident, there's a prearranged signal for the entire company. "It's an emergency call. We immediately swing into 'When the Saints Go Marchin' In' and everybody knows that something is wrong; all the clowns, everybody backstage knows that something has happened and they grab their props, whatever they can get their hands on and dash out onto the track and try to improvise until whatever's happened can be cleared up and the show can continue on."

"There are things going on around the track all the time that nobody has any idea about except us," Batchelor adds. "If someone's hurt, it's always a drag; there's a real sense of loss and everyone on the show feels that. But that's part of the game. If you do an aerial act or a difficult trick, they expect that eventually it's going to happen. It's inevitable. You do something day in and day out, week after week, year after year, most of 'em figure it's going to happen anyway, and they hope it's not going to be too bad. You've got to take your hat off to people like that." Or give them a seven-drum salute.