The Richter Tuning. Richter tuning, refers to the tuning of the reeds in the harmonica. It is named after Joseph Richter, a 19th century Bohemian instrument maker who adopted the tuning for his harmonicas. Most diatonic (blues type) and many tremolo harmonicas use this tuning. Joseph Richter is also credited with inventing the harmonica blow/draw system, this allows the harmonica to play different notes when the same hole is either drawn or blown. Richter tuning is a compromise between a diatonic melody and harmony. The lower portion is used to play the dominant chords, and the remainder of the harmonica is tuned to play in the key of the harmonica.