Top of the Tongue

Simply stated, the more holes you need to block for a tongue block technique, the further back you'll use of the top of your tongue (your tongue is more narrow at the tip and wider at its base). This is achieved by either placing the harmonica deeper in your mouth, to access more of the back of your tongue, or by arching and sticking your tongue out towards the harmonica... and of course, there can be a combination of both.