Major diatonic harmonica - Traditional blues tuning
The major diatonic harmonica was originally intended for playing simple 19th century folk music and its notation layout was adequate for this purpose. The major diatonic harmonica is the most commonly used tuning for playing Blues, Rock, Country Folk and Jazz.
The original playing style, known as 1st Position (Straight Harp), is suitable for playing simple melodies, folk music, and various other types of music that require melody lines, as well as certain chords. 1st position (straight harp), is still used by many players today, but due to its simplicity of sound, it is not as popular as 2nd position (cross harp).
2nd Position (Cross Harp), is a Blues range that offers a more expressive and soulful sound. Most reeds can be bent (a technique used to change the pitch of a note).