Entertainment / Music / Harmonica: Mouth organ: a small metal box on which free reeds are mounted, played by moving back and forth across the mouth while breathing into it.
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Science / Chemistry / Resonance: Description of the ground state of a molecule with delocalized electrons as an average of several Lewis structures. The actual ground state doesn't switch rapidly between the separate structures: it i MORE
Technology / Home Audio / Intermodulation Distortion: A species of Distortion that results when one set of frequencies is superimposed on, or is modified by, another to produce a third frequency not present in the original signal. Quantifies the distorti MORE