The blues harmonica is also referred to as the Richter-tuned harmonica. The blues harmonica also refers to the diatonic harmonica itself, since it is commonly used to play the blues kind of music. It has 10 holes which offer 19 notes with a three octave range. It is designed for a player to play melodies on one single key. For this reason, diatonic harmonicas are available in all keys. It derives the name blues harmonica from the ‘cross harp’ and ‘bending’ style of playing. This is achieved by playing in the key which is a perfect fourth below the key of the harmonica.