2. Structure of the harmonica
With the variety of harmonica construction methods and models it is not an easy task to create clarity. What is common to all models, however, is that they consist of a comb and voice plates. The outer shell and cover of the reed plates represent the cover plates (exception: HOHNER CX12 - it disappears in a housing, and is then closed from behind with a kind of clip).
Chromatic harmonicas also have a slider that can be used to toggle between 2 tones (offset by a semitone).
Depending on the model, the construction and material of the individual components differ:
2.1. The comb
double-channel (see point 3. "The different constructions")
Two-sided playable combs (in the Wender harmonica)
Wood, plastic or metal comb.
Each of the body materials has its own sonic properties.
Plastic has a warm uniform sound. It does not swell when wet
and is therefore more comfortable on the lips than wood.
Wood on the other hand gives a fuller sound.
Metal or metallised plastic surfaces make a bright, clear sound.
2.2. Reed plates
The reeds carry the reeds and are bolted to the comb (nailed earlier). They are traditionally made of brass, some models are nickel silver, nickel or chrome plated. The thickness of the voice plates affects the sound and volume of the harmonica.
2.3. Reeds and Valves
The reeds are traditionally made of brass alloys and are riveted to the reed plate or applied by spot welding (Suzuki). The company Seydel has been successfully producing reeds of stainless steel for several years. They are installed in the models Blues Session Steel, 1847, Sailor Steel and in some Chromatics.
In Chromatics, the reeds are provided with valves to reduce the air loss resulting from twice the number of slots. There are very few unventilated Chromatics, but it will, if appropriate, other models ventilated, for example, blues harps in low-tuning, the Seydel Concerto Octave or the Suzuki MR-350V.
2.4. cover plates
They form the outer shell of the harmonica and traditionally consist of steel or other sheet metal, which can be nickel-plated, (black) -chromed, gold-plated, anodised or coated. Many manufacturers, especially HOHNER and SEYDEL, manufacture stainless steel cover plates to avoid allergic reactions.
The shape of the cover plate has an influence on the sound development of the harmonica. Thus, some cover plates are open at the side, have straight or wavy profiles. What suits best, has to be tried. HOHNER, SEYDEL and SUZUKI offer replacement cover plates for all their harps - applies to Richter harmonicas (Blues Harps).
2.5. The heart of the harmonica: the core octave
Consider channels 4 to 7 of a 10-channel Richter harmonica:
This tone sequence can be found on (almost) all harmonicas, whether Viennese model, chromatic harmonica, Knittlinger or Blues Harp, at least once. It is a complete diatonic octave. However, the question arises as to why the uniform sequence of blowing and drawing in the 7th channel is interrupted. The explanation is to be found in the harmonization: Blowing produces a major chord - c e g c. If one were to interchange h and c, the chord C maj 7 would result. In jazz and Latin American music a very common chord. But not in Europe in these times. Looking at a harmonica with transversely divided channels closer, you can see that the arrangement seems different,
... on closer inspection, however, shows that although blowing and drawing tones are not opposite to each other as in the Richter harp in a channel, but in alternation next to each other, but otherwise our core octave is just as completely available.
The knowledge of the structure of the core octave is very important for orientation, as it can be found in all harmonica models (except for a few special tunings) again.