Analyzing Cross Harp Sounds
When you play cross harp on the C harmonica, you are playing in the key of G. This means that all the scale degrees for cross harp playing relate to the note G instead of C.
To play the G major scale, the note F sharp is required. Just as a flat lowers the pitch of a note, a sharp (#) raises the pitch of a note. This means that the note F# is halfway between F and G. The note F# is not available on the C harmonica, which means the G major scale cannot be played on the C harmonica.
However, the cross harp position is normally used for more bluesy sounds which do not use the major scale but do contain a flattened 7th degree. By flattening the 7th degree of the major scale, the mixolydian scale or mode is produced.
A comparison of the G major scale and the G mixolydian scale is shown in the following diagram.
Here is the G mixolydian scale played first in the middle octave and then over two octaves. Notice the slightly mournful sound produced by the b7 degree. This is one of the sounds that makes cross harp so effective for Blues playing. As you play this example, mentally name the scale degrees, remembering that G is the keynote instead of C. The note G can be found at holes 2, 3, 6, and 9.
Here is a lick which makes use of the G mixolydian scale. Try making up some of your own.
