How to Play Cross Harp With a Harmonica. Playing cross harp with a harmonica shows up a lot in blues, rock with blues influences, and southern rock. It sounds more melancholy than the usual G7 chord, which you produce when you blow on the harmonica, so it's perfect for those more melancholy songs.
Start to play cross harp on the harmonica by sucking in air through the harmonica rather than blowing out on the instrument.
Learn to draw in air most of the time when playing the cross harp on the harmonica. It's a different kind of breath control, so it takes some getting used to, just as breathing through a regulator when SCUBA diving takes some getting used to.
Remember that even though you are playing a harmonica, which is normally in the key of G, the cross harp is in the key of D. This is important information to relay when playing the blues with others. You want to all play the blues in the same key.
Try using the technique of bending chords when playing the cross harp on the harmonica. You can bend the notes by drawing in the air as you play the harmonica with more vigor than usual, which actually distorts the metal reeds in the harmonica, forcing it to play a ½ note lower-actually making the notes flat.
Experiment playing the cross harp on the harmonica on your own or along with blues recordings. In time, you will be able to produce a variety of sounds. Above all, have a great time doing so. A harmonica is an excellent and exciting instrument to play.