" Lastly, he hit on the idea of transferring the observer's position into the centre of the world, and to examine the variations in angular velocity, regardless of distance, as seen from the sun. And lo! it worked. The results were even more gratifying than he had expected. Saturn, for instance, when farthest away from the sun, in its aphelion, moves at the rate of 106 seconds arc per day; when closest to the sun, and its speed is at maximum, at 135 seconds arc per day. The ratio between the two extreme velocities is 106 to 135, which only differs by two seconds from 4:5. - the major third. With similar, very small deviations (which were all perfectly explained away at the end), the ratio of Jupiter's slowest to its fastest motion is a minor third, Mars' the quint, and so forth. So much for each planet considered by itself. But when he compared the extreme angular velocities of pairs of different planets, the results were even marvellous: "At the first glance the Sun of Harmony broke in all its clarity through the clouds." The extreme values yield in fact the intervals of the complete scale. But not enough: if we start with the outermost planet, Saturn, in the aphelion, the scale will be in the major key; if we start with Saturn in the perihelion, it will be in the minor key. Lastly, if several planets are simultaneously at the extreme points of their respective orbits, the result is a motet where Saturn and Jupiter represent the bass, Mars the tenor, Earth and Venus the contralto, Mercury the soprano. On some occasions all six can be heard together: "