When a harmonica is played in its standard tuning, it produces a specific set of notes that correspond to the key of the harmonica. For example, a harmonica tuned in the key of C will produce the notes C, D, E, F, G, A, and B.
In cross harp playing, the harmonica is played in a different key by altering the way it is held and by using specific note bending techniques. This results in a different set of notes being produced. For instance, a harmonica tuned in the key of C can be played in cross harp in the key of G by holding it differently and bending certain notes.
Cross harp playing adds an element of expressiveness and soulfulness to harmonica playing. It allows musicians to create distinctive melodies, improvisations, and solos by taking advantage of the unique tonal qualities produced by playing in a different key.
The cross harp technique is commonly used in blues music, where it is often associated with the soulful and emotive sound of blues harmonica players. However, it can also be used in other genres such as rock, jazz, folk, and even classical music.
Overall, cross harp is a technique that enriches the tonal possibilities of the harmonica, enabling musicians to explore different keys, create unique musical expressions, and add depth and character to their performances.