The idea is not new but it is not that simple. A tone can be mapped to a frequency, this is basically what Tuner Apps are doing. A Chord is built up by multipl

The idea is not new but it is not that simple. A tone can be mapped to a frequency, this is basically what Tuner Apps are doing. A Chord is built up by multiple Tones. There are a lot of techniques - some do it well others fail.