Richter tuning makes the diatonic harmonica unique, but the instrument’s trademark chords (especially in the low octave) requires suffocation of certain notes within the diatonic scale. This is where the big weakness of the diatonic harmonica gets exposed. How is the musician supposed to compensate for those missing notes? Answer: Bending! Problem solved! Not so fast…the bending remedy introduces another very serious problem…stability. The diatonic harmonica’s truncated scales are sometimes glaring. That’s why the worlds most vocal sounding instrument is virtually never heard in many genres. Other harmonicas, like the chromatic, are better equipped with notes. Therefore the diatonic harmonica’s forte (vocal quality) is often sacrificed for the greater musical good, versatility. If bending was the answer, the diatonic would see more playing time. But, the real problem is stability! Stability of its transitional bends are often just a shade off, or unable to be maintained for proper effect. They’re clearly not of a sufficient quality and are oft times completely avoided by the musician. Many bends that do manage to achieve pitch, can still sound as though they were tortured into position.
Sometimes there’s just no substitute for a reed designed to vibrate at a given pitch. Since the ten-hole diatonic harmonica is missing crucial notes in its scales (Richter tuning,) it can sound like amateur hour when trying to render a more complex musical piece.
The logical answer is to couple diatonic harmonicas in such a way that those truncated diatonic scales are filled out. A bonus to coupling harmonicas is that through the process chromatic notes become present enabling even more convincing deliveries. The interesting thing about coupling harmonicas is that you give up nothing that the instrument already offers, amazing personality, and bending for the most part becomes a tasteful embellishment instead of an absolute necessity.
Coupling is easy and inexpensive. The coupled diatonic will out perform any of the exotic expensive hybrids that are popping up as the “remedy” for its lack of versatility.