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Playing Chromatically

The Bahson Overblow harp

Tested model: Bahson Overblow harp based on the Hohner Golden Melody.

The overblow technique requires two actions (given here for the 6 first holes):

  1. Prevent the blow reed from vibrating.
  2. Make the draw reed vibrate.

This is of course the opposite for hole 7 to 10.

The first action requires choking the reed. A gap reduced to the minimum and a proper breathing technique are necessary.

The principle of the Bahson Overblow harp is to allow the player to more easily achieve the overblows by pressing a slide: when pressed, the slide blocks the blow reeds in holes 1, 4, 5, and 6 and the draw reeds in holes 7, 9, and 10 allowing the player to concentrate on making the opposite reed vibrate.

The slide only acts on the reeds that would supply the notes missing from the chromatic scale. For example overblows are not facilitated in holes 2 or 3. Why? Because the notes that would be produced are already available by other means. But what would be the value of including them?

Let's say we have a harmonica in C and the player wants to arpeggiate and Ab7 chord. That's one semitone above a G7 chord. So why not just play overblows in Holes 1,2,3,4,5? This is not an intellectual exercise. Players like Allen Holmes do exactly that. On a Bahnson harp, the player would instead have to play Overblow 1, draw 3 bent 3 semitones, blow 4, blow 4 OB, OB 5. Much more complicated.

Moreover, an isolated reed can not only overblow, it can bend the overblow up in pitch several semitones. Let's say you're playing blues in G on a C harp. Db is that all-important flat 5. The usual way is to bend down to it from Draw 4. But what if you could bend UP to it? Overblow 3 would allow you to start on the 4th degree of the scale and bend up to the flat 5.

Is it a major drawback? It is likely that advanced players think so as this limits their expression. But intermediate players would most probably not be bothered by that.

This design was invented by Dr. Henry Bahnson in 1990. A first batch of harps, based on the Golden Melody were commercialized. This is the modele we've reviewed.

The Turboharp company has designed a new version based on the Special 20.


  • Very Small.
  • The overblows are extremely easy to play and clean and can be sustained with vibrato.
  • No need of gapping low: the harp can be played really hard.
  • It is probable that the price will not be too expensive.


  • Not commercialized so far!
  • Not really a customized instrument. Very playable but not exceptionally airtight.
  • The player has to deal with the slide and has to be careful not to push it while blowing as this could hurt the vibrating reed.

How to play it:

The Bahson Overblow being a richter harmonica, playing chromatically implies to master the overblows. See the standard richter harps chromatic playing page.


The Bahson Overblow harp is a very good design which definitely eases the overblows and allows to play the regular notes very hard. As such, this would be a very good solution for the keys more difficult to overblow.


We've asked James F. Antaki (from AntakaMatics, Inc.) what were his plans regarding the Bahson harp. His answer is that the Bahnson overblow based on the Special-20 currently exists but is very complicated to mass produce. As a result, his higher priorities are the new TurboHarp/AX and the ELX. Both are moving along slowly (prototypes exist but mass production issues are slowing down the release to the public).

Laurent Vigouroux