Here is the complete text of an 1886 interview given by American circus man John Robinson (I've posted the link in a couple of threads.) Interesting for both the intersection of circus music and circus animals; and the American circus as popular music medium/distributor:

CIRCUS MUSICIANS.

The Difficulties of Selecting Music for the Performance.

WHAT THE LEADER'S DUTIES ARE.

Time and Tune Must Be Adapted to the Character of the Work in the Ring – Men and Horses That Cannot Stand Any Change.

"Once a man gets into the life of a circus band," said the leader, and accustomed to its hard work, he likes it, and very few care to leave it again for the casual and chance engagements of unattached musicians. Even if they were so fortunate as to get places in regular theatre orchestras they would have their dull season each year, and, when at work under union rates, would only get $2 50 a performance, out of which they would have pay. their personal expenses, so that they would be no better off than in a circus. Then, there is no small attraction in, the travel, excitement, open-air life and variety of a circus. Some of our circus band-men go on playing until they are quite old.

"It is the duty of the leader to select and arrange the music for his band in a circus just the same as any other band, but the circus leader has much the hardest work to do. In the first place he must have such an immense quantity of music, as you will readily conceive. But, still more difficult for him, if he does not thoroughly understand the circus business, is the selection of the particular airs that will fit to the various performances in the ring. That would not be so hard too if there was only one ring and one performance in it at a time, but when you have from three to five various performances going on simultaneously you don't find it so easy to pick out music that will trump in or follow suit with them all.

TIME AND MUSIC TO SUIT.

"If there are two or three riding acts simultaneously, it will be comparatively easy to fit them, but when you have things going on upon the ground and in the air at once, you must be very careful or you will throw your horses or your people out. Then you have to know which one of the lot is most important, to which you will have to play, making the others secondary, but serving them as well as possible at the same time. For instance, when the stars are doing their really wonderful triple trapeze act, though 'there are three other acts going at the same time, I have to play for the stars and must control the time and force of the music to suit them. When he sounds his bell the band has to play pianissimo, for that is the signal that he is about to speak a word of direction or warning to the girls, and his voice must be heard. And when one of their astounding feats has been performed, the band must break out with a fortissimo crash, blending with the roar of applause from the audience. No matter where the writer of the music may have put his diminuendos or crescendos, I have to play it that way, whether the piece becomes unrecognizable or not, whether it may suit the other performers or not, and whether people say 'how badly the band plays that air' or not, for it may be a question of limb, if not of life, to have it done in just that way.

"One thing that gives, necessarily, a certain sameness to much circus music is the compulsory emphasis of notes in regular recurrent order, not demanded at all for musical expression, but very requisite for marking the time for the horses in a menage act, or some other riding. If you do not thus sharply accent the time the best trained horse is liable to be all broken up and make a failure of his performance. When I was with Hengler many a time I had to go with my violin to the ring at 6 o'clock in the morning to play by the hour near a horse that was undergoing training, so as to familiarize the animal with the air to which he would be required to perform in the ring. Hengler would have a horse in training in that way as much as three months steadily before trusting him in the ring, and he was very careful never to allow the time to be made slower or more rapid, to suit the horse, but kept regular, until the beast fell naturally into the step to it.

PLAYING THE "SAME OLD TUNE."

"Here there is so much careful training, and we have to adapt the time to the horses, to a certain degree, but still the marked accent must be kept, and that is enough to make a very strong family resemblance between tunes; enough to make many people say 'same old tune.' The elephants and the trained stallions require to have always the same music, or if not nearly the same, then so very near to it that the animals cannot recognize any difference. Of course we do work in some changes on them, but not abrupt ones, for the American public will not stand the same thing all the time, no matter what the preferences of the animals may be. When I was in England, seven years ago, Hengler's band was playing the same music for menage and trick acts that they had played for seven years before, and I have no doubt they are playing the same pieces now. That would be likely to breed a riot in this country, I think.

"Many trapeze and other specialty performers have music of their own, and when we can accommodate them by playing it we always do so. Generally, however, their music is arranged for string bands to be used in theatres and variety shows, and we could not play it without rearrangement, which would be too much trouble so long as we can supply other music quite as good. The lady who does a fine trapeze act and the long elide on the inclined wire has some beautiful Spanish music, and as it suits very well for the triple trapeze act, which is on at the same time, we play it. Now and then we work in a new piece on her, and she is very good-natured about it, always saying, 'All right; but after two or three days she is sure to come and say, 'Please, Mr. Robinson, let me have my own music again.' She can work better with the music to which she is accustomed. The trapeze performers also have their own music for their special work. Mme. Dockrill was very particular about her music, and need always to sing with the band, but of course in a tone that the audience could not hear, when riding in the ring. She no doubt got into the habit while training her horses in Winter, accustoming them to the measure of music for their movements. Jim Robinson, the great bareback rider, had a certain set of quadrilles that he always insisted upon having played for him, and he would not ride to anything else. Fish, on the other hand, though he had quite a fondness for music and used to practice on the violin in his dressing-room a good deal, did not seem to care at all what was played for him in the ring. Stickney and Melville were very particular to have each season new sets of quadrilles and other melodies for their acts.

(Circus Bandmaster & Proprietor John Robinson, Daily Alta California, Friday, July 9, 1886 p.2)