The use of local anesthetics in dentistry has made possible the painless extraction of teeth. Most dentists, however, do not inject local anesthetics before drilling cavities. For many people, drilling is a frightful experience. Some dentists have advocated the playing of music at a loud level during this procedure. Still another has incorporated ear-phones into the head rest of the dental chair for diversional sound. A more obvious use of diversional sound in the professional office is in the reception or waiting room to supplement the magazines and diminish the terror of waiting. Music may also be used during such time-consuming treatment as physical therapy, deep x-ray therapy, and fever-therapy. PHYSICAL EXERCISE Some forms of physical exercise are carried out most successfully when accompanied by music. Plato recommended such a practice in his _Republic_. In the ancient triremes or boats with three banks of oars, there was always a tibicen or flute player, not only to keep uniform rhythm among the workmen, but to sooth and cheer them. From this custom Quintillian took occasion to say that music enables us more patiently to support toil and labor[15]. During the Six-Day Bicycle Race at the Madison Square Garden in 1911 forty-six mile races were separately timed on three evenings; half were ridden to music. The average time with music was 19.6 miles per hour, and without it only 17.9[5]. Tarchanoff found that “if the fingers are completely fatigued, either by voluntary effort or by electric excitation, music has the power of making fatigue disappear.”[74] Such an observation leaves little doubt that physical endeavor is more productive when done to music. _Calisthenics._ This is not the place to discuss the value of calisthenics or its use in hospitals. Exercise has come to be considered the important physical conditioner, and calisthenics is the universally practiced exercise. Its proper performance will depend upon the ability of the leader, the willingness of the participants and the ingenuity expended to make it interesting. The willingness of the group can be enhanced by large numbers of performers, but under any circumstances, since it is unproductive and involves work, any adjunct which will increase interest is welcome. The exponents of both the Swedish and the German systems of calisthenics claim equally good results, but the former do not use any musical accompaniment, whereas some schools in Germany, particularly the one at Hellerau, make extensive use of it. In fact, Dalcroze and his followers have built an entire philosophy of esthetics called “Eurhythmics” based upon the relationship between body motion and music. Unproductive exercise can undoubtedly be made more interesting by musical accompaniment. Music can regulate the orderliness of action by relating the sense of hearing to the sense of muscular movement.