Tongue Blocking Tips - Why 4 Holes

Yesterday I stated that your lips should be surrounding four holes. The purpose of this is as follows, with the more important reasons listed first...

1) You can play an octave very quickly with slight adjustment of the tongue (to the center, blocking two holes).

2) Your slaps, pulls, flutters and other techniques where the tongue is off of the harmonica have a much bigger sound, due to there being four holes sounding when the tongue is off instead of three.

3) Since the harmonica is deeper in your mouth, your mouth is larger, creating a larger resonant chamber, and this provides you with a bigger tone.

4) You can move your tongue to the right so that the lower hole in your embouchure is the octave below the note you were just playing (a very common technique used on the V-IV-I Transition in Bars 9, 10 and 11).