This article is about the many and varied ways that innovative harmonica designers and players are pushing the boundaries of the harmonica to reach the optimum marriage between that earthy expressiveness (generally associated most with the 10 hole single reed diatonic harmonica, often called the blues harp), and full chromatic facility, which up till the recent past has been typified by the more 'refined' sound of the standard chromatic harmonica (generally a 12 hole model, with a slider which activates the sharps and flats). Until the mid 1980's, the chromatic was accepted as the only harmonica on which to play more 'advanced' music, and all the star classical and jazz players (Larry Adler, Toots Thielemans etc) played the chromatic harmonica.
However, there is a strong movement now, inspired by the work of the American player Howard Levy, to play chromatically on the 10 hole diatonic harmonica, using techniques such as note bending and overblowing which force the reeds to adopt pitches other than their naturally-tuned ones; in the hands of a skilful player, these give a full chromatic scale on a diatonic harmonica. This is where the most high profile action is in the harmonica scene right now, and it's pushing the development of some highly interesting new diatonic harmonica designs which exploit the unique ability of the harmonicist to make those little reeds to do some wild and crazy things by subtle changes in embouchure alone.
However, there are some other approaches which promise to give the same happy marriage between full chromatic capability and maximum expressiveness which are not so well known now, but may point the way to the future. These are fascinating times for the harmonica, and this article will be a broad overview of the current 'State of the Harp', and my speculation on the way ahead for instrument design and playing techniques.
Two Basic Designs Of Single Reed Harmonica
Though the harmonica comes in various double reed designs (tremelo and octave tuned solo instruments, plus the bass and chord harmonicas), like accordions, these do not offer note bending possibilities. It is the single reed harmonica's very simplicity of construction and playing method that is the source of its unique expressiveness. It comes in two types: the Richter tuned 10 hole 20 reed model, commonly known as the 'Blues Harp', and the chromatic harmonica, generally a 12 hole model with 48 reeds. The common factor between them is that there is only one reed per note in the scale of the instrument - but in all other respects they are quite different.
The blues harp is free reed design at it's most basic: a ten channel body, made of wood, plastic or alloy, two reedplates (the top one containing the blow reeds, the bottom one the draw reeds), and a couple of coverplates to protect the reeds and hold the instrument.
The most famous model is Hohner's Marine Band, which featured on most of the blues recordings by such early masters as Little Walter, Sonny Boy Williamson II, big Walter Horton, Sonny Terry etc. The 10 hole diatonic is now made by other manufacturers such as Suzuki, Huang, and Tombo, but the basic design is still the same: a blow reed and draw reed in each air channel, with no mechanical moving parts. In short, the most direct interface between the player and the reeds themselves. It was intended for simple folk melodies, and comes tuned in the diatonic Richter tuning, which gives a three octave range (though three notes of the scale are omitted to achieve this). Each octave has a different scale arrangement, the bottom one intended for chordal accompaniment, and the top two octaves for melody. Since it is a diatonic instrument, it comes in all 12 keys.
The chromatic harmonica is essentially two diatonic harmonicas in one instrument. It also has two reedplates, but blow and draw reeds on each one, and four reeds per air channel. A sprung slider selects just two of these at any one time, and is activated by the player to give a full chromatic scale. Due to the inevitable air loss that the slider incurs, windsaving valves are added to the reeds, so that when a player blows a note, the opposite draw note is sealed off - and vice versa. The range of the twelve hole model is still three octaves, but the scale is arranged to include all the notes and provide an identical pattern in each octave. Larry Adler was the great populariser of the instrument, but great players like Toots Thielemans and Stevie Wonder have introduced it to modern listeners. The chromatic generally comes only in the key of C, although others are available.
The Source Of The Harmonica's Expressiveness
It is the directness of the player's breath to the single reeds that makes both harmonicas so expressive. It was soon discovered by early players that by altering their mouth shape and attack they could get those little reeds to do things far beyond play their basic pitches - to the extent that these techniques have now come to almost define the very sound of the harmonica.
Pitch Bending is the defining sound of the diatonic, and is what made it such a perfect instrument for the blues. On the blues harp there are no valves, which means that when you blow and draw, there is an interaction between the two reeds in each air channel. Normally this means you just get the two notes alternately (say a D on the draw and a C on the blow). However, when you alter your embouchure on the draw note, it can be made to bend down in pitch almost to the blow note. In this case, you can bend the D down to a Db, but the same rule holds for any other note pair on the harp (indeed, in the Richter tuning, there is a draw B above a blow G on hole three of a C harp, and this means the B can be bent down to Bb, A, and Ab, as well as play it's own pitch). Getting these notes in tune is simply a matter of practice (just as a violinist pitches his/her notes by ear), but once the technique is mastered the diatonic blues harp suddenly has a whole range of extra chromatic notes.
It was assumed until recent times that the reeds did what you heard them doing: i.e., the high one bent down to the low one. However, surprisingly, the opposite is the case: on an unvalved instrument like the blues harp, it is the low reed that rises in pitch. Therefore, when you suck down on that D and it seems to drop smoothly to the Db, it is actually the blow C which is making the sound - even though you're not blowing! This is totally counterintuitive, but true nonetheless., and it holds even if the blow note is higher than the draw: in that case, the blow note seems to drop in pitch, although it is the draw reed that is rising.
On a valved instrument like the chromatic, there is no interaction between the two active reeds, but bending is still possible by altering your embouchure. It is a lighter, less earthy bend, and very difficult to hold steady in pitch, but it is still very expressive. Stevie Wonder uses it to great effect, allowing him to bend up to or off notes, and add vibrato. Since every reed is valved on the chromatic, the same technique can be applied to each note (ie. the draw D and blow C can be bent down).
However, on the diatonic, while the high note in each hole could be bent, the low note seemed to be impossible to affect in any way - until Overblowing was discovered. This is an even more bizarre effect of the interaction between the two reeds on a diatonic, and works the opposite to pitch bending. If we look at the D draw and C blow notes again, when you blow on the C and alter your embouchure correctly, the note seems to pop up to an Eb! That's an overblow - or overbend, as some call it. Initially the sound seems hoarse and shaky, but again with practice and correct setting up of the reeds it can be made into a clear note.
What's happening? Well, it turns out that when you overblow the C, it is actually the draw D that is rising a semitone to the Eb! Again this seems to run counter to common sense, but it is indeed the case, and it holds true for any other blow/draw pair of reeds on the harp. Even if the draw reed is lower than the blow, if you suck on it with the correct mouth shape, it will seem to rise in pitch to a semitone above the blow note - but it is actually the higher blow reed that is rising.
When bending and overblowing are combined on the humble blues harp, suddenly the instrument is capable of a fully chromatic scale - leading to all sorts of possibilities which weren't conceived of before. However, since there is no interaction between the reeds on the valved chromatic harmonica, overblowing is not possible on the standard instrument - and it is not required, since all the chromatic notes are available anyway.
The Present Scene: Diatonics Rule OK
While for a long time the chromatic was regarded as the 'serious' player's choice of harmonica, in recent years all the action has been on the diatonic. The American jazz player Howard Levy is the foremost proponent of the overblowing approach; his astonishing mastery of the technique, combined with a highly developed musical knowledge, has allowed him to take the lowly blues harp into musical styles which were formerly not possible on the instrument, such as bebop, experimental jazz/rock fusion, classical music, and Arabic/East European styles. Many players have followed his lead, and there is now a whole overblowing school developing. It is becoming a mainstream technique, to be learned along with bending notes as part of mastering the instrument. You can check out more on Howard at his web site. Another influential overblower who works more in the Rn'B vein is Carlos Del Junco.
Innovative New Designs
However, even on a well set up instrument, overblowing is still a very difficult technique to master, especially throughout the range, and several new designs have been developed to make it easier to achieve clear and strong overblows on all notes. It was noticed that if the lower pitched reed was stopped when a player was overblowing, it made the overblow far stronger and easier to achieve, and this principle has been put to work in three different designs.
The first of these, Henry Bahnson's Overblow Harp, was a modified Hohner Golden Melody model with a slide that, when activated, moved over the surface of the reedplate to cover the relevant reeds. However, it was complex to make and use, and was never sold in big numbers.
Another approach was adopted by Winslow Yerxa with his Discrete Comb model. This divided the blow and draw reedplates into separate air channels one above the other, and the player could either play both together or isolate them as he/she desired, thereby enhancing both overblows and bends. Unfortunately, it seemed impossible to realise the design without making the harmonic substantially thicker than normal, which felt uncomfortable in the mouth for many players.
The most recent and promising of these approaches is the Overdrive MR300 harmonica, designed and produced by Suzuki of Japan. It employs special coverplates; whereas the normal ones comprise simply a single large soundchamber which covers all the reeds on a particular reedplate, the Overdrive has coverplates with airtight divisions, giving each reed its own sound chamber separated from the others, and having a hole at the rear end. When a player stops this hole, it dramatically improves both the overblowing or bending possibilities, depending on which reed is affected. The instrument is still awkward to hold and play, but future design improvements should improve this.
A different approach to overblowing, but which is also intended to enhance the expressive and chromatic abilities of the diatonic harmonica, is to allow more notes to be bent in pitch. The Suzuki ProMaster MR350V is a half valved diatonic, which employes chromatic-style valves that work only on the lower pitched note in each air channel. This allows the lower note to be bent down in the same way as on a chromatic, giving the harp more expressiveness, while the higher notes can still be bent in the normal way. However, the valves alter the traditional breathy diatonic tone, and the valved bends are difficult to control as chromatic notes in their own right. Along with the concurrent rise of overblowing, these factors have meant that the half-valved diatonic has never achieved mainstream popularity.
A more radical approach with the same aim in mind is taken by Rick Epping in a patented design using what he calls Enabler Reeds. These are extra reeds added to the air chamber which enable more reeds to be bent down in pitch by reed interaction, giving the extra notes not available on a standard instrument. Although only a few prototypes have been made so far, this is a promising idea as bending notes is a lot easier for most people than overblowing. Furthermore, the quality of the bent notes tends to better: they are clearer, thicker, and more expressive than overblows. However, the Enabler Reed instrument will be complex to build and sell at a competitive price, and it remains to be seen whether it will become commercially available.
It is always difficult to predict the future, but in my opinion the next ten or twenty years will see an increasing convergence between diatonic and chromatic designs. Though all the present action is with the diatonic harp, even with overblowing and note bending, the diatonic still has limitations or difficulties which are overcome in the design of the chromatic. For example, the type of trills and decorations possible with the slide are impossible on the diatonic. Also, playing the bent and overblown notes at speed with accurate tuning is very difficult, and can easily lead to out-of-tune playing that is hard on the ear. However, on the chromatic harmonica, all the chromatic notes are available as normally blown notes, and therefore their tuning is inherently accurate.
There is already an historical precedent for this, as the first chromatic harmonicas made back in the 1920's were unvalved Richter tuned models. The Koch harmonica is still made this way, but it suffers from very poor airtightness and has never been popular. The Hohner Slide harp is another Richter tuned chromatic, but this one overcomes some of the airtightness problems by half-valving, as on the Suzuki ProMaster. However, it is still not very airtight, and has not achieved much popularity.
My own approach is to use more airtight chromatic designs, like the Hohner CX12, and then modify them by retuning the scale and half-valving. This gives an acceptably airtight instrument which has a lot of enharmonic notes available either through normal playing or note bending adjacent reeds. However, though I endeavour to make my chromatics as airtight as possible, they still need to be half-valved. This means that overblowing is not possible, and the tone is not the same as on an unvalved diatonic - and these factors, as well as the instrument's larger size (meaning hand effects are not so easy), would be considered drawbacks by staunch diatonic overblowers.
To fully achieve the airtightness and gutsy tone of the diatonic in a small sized, probably Richter tuned chromatic harmonica will require a completely new design, with extremely tight reed tolerances. It may be an impossible task to completely marry the two instruments, but that won't stop people trying, as the potential for the optimum marriage between expressiveness and full chromaticity is too much of a lure to resist. Given the general buzz in the harmonica scene at the moment, and the current pace of innovation, I think it won't be long before advanced new designs bring this goal closer to realization. - Brendan Power
Article, sound files and images are all ©2000 Brendan Power, and used by the authors permission