Music of the Sphere:
According to a report just published in Science, the Earth gives off a musical sound, because it is continuously vibrating. Japanese scientists have measured the very low frequency (in the range of once every 200 seconds). This is in addition to the vibrations caused by occasional earthquakes or volcanos: a bass note. It is assumed that the Earth is oscillating in resonance with the atmosphere. The amplitude of the oscillation varies, reaching its peak in July and August -- the theory is that the movement of warm air to the top of the atmosphere results in convective cycling that results in dynamic pressure affecting the slow oscillation.