Brendan Power Signature
Brendan Power


Overblowing is the common term for an increasingly popular technique used by players of the 10-hole Richter diatonic harmonica to obtain missing chromatic notes on the instrument. A more accurate term is "overbending", because it can be done on both breath directions: blow notes are raised with overblows, and draw notes with overdraws. Even though they are different, the widely-used term that applies to both is Overblowing. Combined with traditional interactive-reed bending (which lowers reed pitch), overblowing raises the pitch; using both techniques players can achieve a full chromatic scale on an ostensibly diatonic instrument.

But it's not quite that simple. For overblowing to work well, the harmonica needs to be finely adjusted, with close reed gaps and slot-embossing. Out-of-the-box harps will overblow, but any serious player who uses the technique will either buy expensive hand-customised harps, or spend considerable time working on their own harps to optimise them for overblows and overdraws. Even with such customisation, overbending is a high-level playing technique that takes years to master throughout the whole range of the harp. As a result, the number of really good overblow players in the world is still small, even 40 years since the technique became widely known. Harmonica chat groups are littered with posts describing the struggles of beginners trying to incorporate overblows and overdraws in their playing.

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My Overblow Booster makes overbends much more user-friendly, enabling total beginners to overbend with ease straight away - all the way from hole 1 to hole 10! For advanced players, it enhances their sound, volume and expressiveness. It gives greater control of both overblows and overdraws, allowing easier bending of them, adding soulful expression such as vibrato on overbends, plus new effects never before possible. The Overblow Booster works great on standard harps without any special gapping or embossing. Even the difficult-to-get overblow in hole 1 is now a breeze to get on a stock harp out-of-the-box! On a fully customised harp the overblows will sound and play like butter, sounding as strong and expressive as standard bends, and give expert overbend players a whole heap of extra fun. Watch the video to see/hear for yourself.

For a long time it's been known that if you stop the lower-pitched note in a chamber from sounding, the overblow/overdraw plays much more strongly. Various harps have been created in the past to make this happen, but none succeeded - because they were either too complicated, too expensive (often both), and forced players to buy new harmonicas. My Overblow Booster is far simpler, cheaper, and doesn't require you to buy a new harmonica: it can be added to your favourite harps in under a minute, and removed just as quickly!

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The Overblow Booster only works with harps that have open-back covers. These include the Hohner Crossover & Marine Band Deluxe, Seydel 1847, Suzuki Manji, and some of the models from the excellent new Chinese brands Easttop and Kongsheng. Make sure the harp you are ordering for has open-back covers; select the brand and model in the drop-down list. It comes in two versions: Basic and "Full Monty". The Basic version comprises two light ABS plastic parts that sit almost invisibly beneath the coverplates, fitting snugly to the harp with small tabs that correspond to the reedplate screw positions for each model. The open outer ends of the individual reed channels can be closed with your fingers as you play, thus stopping the inactive reed and making the overblow/overdraw much stronger, and play with greater control.

The Full Monty version adds the Booster Bar: a rear hinged lever attached at the bass end of the harp that closes all the coverplate channels with one quick movement - thus avoiding the need to select the individual channels with your fingers. The Booster Bar's neoprene pad seals to the channel openings when closed, but the harp plays normally when it's held away from the back. It doesn't affect the tone of the harp, hand wah-wah effects can be used on all notes (including overblows/overdraws), and it works well with a handheld microphone too. Watch the first video from 9:15 to see the Booster Bar in action!


The Overblow Booster requires harps with open-back coverplates, such as the ones listed below. However it can be added to other harps (eg. Hohner Marine Band 1896) if the rears of the covers are opened up. Here are the prices for the Basic and Full Monty options; choose the harp model that you want to fit your OBB to.

Overblow Booster


(Large Price Reductions for Multiple Buys!)

Overblow Booster Options
(NB: The Booster Bar only works with the Inserts inside the harp):


Overblow Booster

All prices include international shipping. Orders over £60 will add Tracking
Update 14 July
I've now updated the Hohner version of the Booster Bar to a quick-release attachment system: it can be snapped on and off in seconds, and you can switch it over to another harp. This means for Hohner harps, if you wish, you only need one Booster Bar for multiple harps. This saves you money! Check out the Quick-release Booster Bar in this video 0:10-1:45 I'm developing the quick-release system for the other brands/models - but for now, they all have the screw-fit Booster Bar.

FITTING - it's a Breeze!

If you want to get playing straight away, simply remove your coverplates, position the two parts of the Overblow Booster in place, replace the covers and start overblowing! The longer part goes on the blow reedplate, the smaller one on the draw reedplate. It’s pretty obvious how they fit around the reedplate screws; watch the video on the main page from 7:20. However, I recommend you take a bit more time to get the seal on the lower surface of the Overblow Boosters really airtight. For a demonstration of some simple steps you can take to that end, as well as advice on fitting the Booster Bar, please watch the video below.


Check out the in-depth review and demo of the Overblow Booster by Christelle Berthon in this video.

Subscribe to Christelle's popular YouTube channel .

" Finding that the one and four overblow adds many new options to first position blues !! Having fun with that. Still tweaking the harps but the overblows and overdraws are coming easier now. Thanks again for your innovation. "

Joe Galicic (July 2018)

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