While the whistles attached to the pigeon's tail in the main article's photograph appears to be heavy, making flight difficult, they most definitely are not.
The whistles are made of very, very light weight materials such as shellacked paper or bamboo. The rather substantial pigeon whistle shown here weights only one half once, or 14 grams if you are more accustomed to that weight measurement type
...it is not the pigeon that profits from this practice, but merely the human ear, which feasts on the wind blown tunes, and derives aesthetic pleasure from this music.
We are wont to speak of the Chinese as a sober, practical and prosaic people, and to view them throughout in that light. Immensely rational they are, secular and worldly minded, bestowing their efforts on useful temporal affairs; but, nevertheless, they are by no means lacking in purely emotional matters of great attractiveness. As early as the 11th century one of their great poets sang:
"Upon the bridge the livelong day,
I stand and watch the goldfish play."
The domestication of the goldfish, the first species of which reached England in only 1691, and of the wonderful paradise fish as well, is justly ascribed to the Chinese, and it is remarkable to note that their attempts in this directions and the amazing results achieved were not prompted by any utilitarian views they had in mind, as neither fish is of any practical advantage. On the contrary, their skillful breeding, so eagerly pursued, is due solely and exclusively to the aesthetic tendency of the Chinese in their art of living and to their highly cultivated sense of beauty, which delights in the bright coloration of the skin of these fishes, the graceful form of their bodies, and the restless motion of their long flowing fins.
While the almost Darwinian experiments to which the Chinese breeders have subjected the goldfish, and their unbounded admiration of this little creature in its hundred and one forms and variations, illustrate well the intimate relation of the people to the element of water, their friendly associations with the world of birds are not less close and sympathetic. The lover of birds does not permanently confine his pet in its prison cage, but he takes it out with him on his walks, carrying it on a stick, to which one of its feet is fastened by means of a thread long enough to allow it ample freedom of motion. Where the shade of some stately tree bids him welcome, he makes a halt and permits the bird to perch and swing on a simple twig, watching it for hours.
One of the most curious expressions of emotional life is the application of whistles to a flock of pigeons. These whistles, very light, weighing a few grams, are attached to the tails of young pigeons soon after birth, by means of a fine copper wire, so that when the birds fly the wind blowing through the whistles sets them vibrating, and this produces an open air concert, for the instruments in the same flock are all different. On a serene day in Peking, where these instruments are manufactured with great cleverness and ingenuity, it is possible to enjoy this aerial music while sitting in one's room.
There are two distinct types of whistles-- those consisting of bamboo tubes placed side by side and a type based on the principle of tubes attached to a gourd. They are lacquered in yellow, brown, red, and black to protect the material from the destructive influences of the atmosphere. The tube whistles have either two, three, or five tubes. In some specimens the tubes are made of ox-horn instead of bamboo. The gourd whistles are furnished with a mouthpiece and small apertures to the number of two, three, six, ten, and even thirteen. Certain among them have besides a number of bamboo tubes, some of the principal mouthpiece, some arranged around it. These varieties are distinguished by different names. Thus a whistle with one mouthpiece and ten tubes is called the eleven eyed one.
The explanation which the Chinese offer of this quaint custom is not very satisfactory. According to them, these whistles are intended to keep the flock together and to protect the pigeons from attacks of birds of prey. There seems, however, little reason to believe that a hungry hawk could be induced by this innocent music to refrain from satisfying his appetite; and this doubtless savors of an afterthought which came up long after the introduction of this usage, through the attempt to give a rational and practical interpretation to something that had no rational origin whatever; for it is not the pigeon that profits from this practice, but merely the human ear, which feasts on the wind blown tunes, and derives aesthetic pleasure from this music.