Hello! In today's harmonica lesson I'll teach you how to make overblows much easier with a simple adjustment to the reeds. New to overblowing? Check out Overblows for Beginners and Top 5 Overblow Problems (and Solutions)
What is gapping?
'Gapping' is adjusting the height of the tip of the reed relative to the reedplate. It's a fine balancing act, but this simple adjustment can make overblows much easier.
Some background information: the gap between the tip of the reed and the reed plate determines the amount of breath you will need in order to make the reed vibrate. If the gap is bigger, you need more air. If the gap is smaller you'll need less air. However, the reed won’t play at all if the gap is too small, since the air needs to pass through to vibrate the reed.
So how does gapping relate to overblows? Well, a smaller gap will make the overblow come more easily because it will be easier to 'choke' the blow reed and manipulate the pitch of the draw reed (this is crucial to playing overblows).
Above is a side view of the reed (as if you are looking down the length of the reed plate) before and after gapping. The large gap is very exaggerated in this image, but it gives you an idea of what you’re aiming to do.
How to gap a reed
Gapping is simple but fiddly. Remove the cover plates and use something small (a screwdriver or tooth pick) to push the tip of the reed gently to narrow the gap from the reed to the reed plate. Play the reed to check that the ‘normal’ note will still play before putting the cover plates back on. If the note is delayed or you can’t play at the volume you want, open up the gap again – it’s a balancing act!
You need to reduce the gap on both blow and draw reed so that the overblow is easier, but there still needs to be a big enough gap to play the natural notes at ‘normal’ volume.
Each player’s normal volume will be different. Lots of overblow players get used to playing pretty softly so that they can gap closely and make the overblows easier.
More overblow tips
Choose the right harmonica
The cheapest harps will really struggle with overblows. You need something that is pretty airtight and made fairly well. You don't have to spend a fortune, but if you got a free harmonica with a teach-yourself book, it's very unlikely to produce good overblows. Mid-range instruments such as the Hohner Special 20 and Hohner Golden Melody work fine. Suzuki Manji, Olive and Promaster will work great too. Lee Oskars don't overblow very well.
Consider your level
It's really important that you only try to overblow once you're comfortable with draw- and blow-bends, otherwise you'll really struggle to play overblows properly.
The word 'overblow' is misleading. It suggests that we have to blow harder to get the technique. However, if you just blow like mad then you won't get the overblow and you're also likely to break your harp. It's about a change of pressure and angle, rather than force. Be ready to make subtle adjustments to your mouthshape and pressure.
Need more help with overblows?
Would you like to take the perfect starter course on how to overblow? Learn the basics of setting up your harp for overbending, work through scales and explore how to add both overblows and overdraws to your existing playing.
With the course, you'll get:
Step-by-step instruction to get you overblowing for the first time
Short lessons in easy-to follow chunks (using a C diatonic harmonica)
How to set up your harp to make overbends easier
Scales and exercises to add overbends to your playing
Find out more about the course structure here.
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