The innovative Earthworks PianoMic System required the design of unique high definition microphones. Virtually all microphones used for recording and sound reinforcement are “free field” microphones, designed to pick up sounds in front of them. In contrast, the microphones in the PianoMic™ System are actually placed within the sound field of the piano, where sound is coming at the microphones from multiple sources and multiple directions. Each string is a separate sound source and the soundboard is also a sound source. In addition, there are multiple reflections of each sound source from the soundboard, piano sides and piano lid. These reflections, arriving from different angles, create what is known as a “diffuse sound field. ” A “random-incidence” microphone is designed to be placed within such a diffuse sound field and pick up sounds uniformly, whether they arrive at the front, the sides or the rear of the microphone. The PianoMic™ System achieves much of its remarkable performance through the use of specially designed, 40kHz random-incidence High Definition Microphones™.