One of the more common questions I receive from beginning blues harp players is whether to use the draw on hole 2 or blow on hole 3. This is a valid question because they are the same note. However, if you play each one and really listen to the sound of the harmonica you will hear that while the note is the same the inflection and tone of the note is not. For most peoples’ ears, the draw 2 note sounds more gritty and powerful. This is why when playing blues, the draw 2 is king. Also, the draw 2 is the “home base” or root note for playing Crossharp.
While it is preferable to play the draw 2, it is perfectly ok to use the blow 3 as a passing note in order to keep the airflow moving in the same direction which might be needed to play a lick that goes by rather quickly.
Experiment with the Hole 2 draw and hole 3 blow and let me know what you think.