People often ask me why I don't play a chromonica or play on different key bluesharps.
Some people are of the opinion that a harmonica is a harmonica no matter what type or model so you'd better choose "the right tool for the job".
I don't think of the different harmonicas that way. To me the diatonic harmonica is as different from the chrom as a trombone is from the trumpet. Both may use the same principle to generate sound but there is a world of difference in the way they are played and in the way they sound. And as far as chromatic harmonicas go, I have a short and blunt answer: I don't like them.
Don't get me wrong, I know some wonderfull chromatic players and they make beautifull music on the chromatic, but I am a diatonic harmonica player and I just don't like the feeling of playing a chromatic. I don't like the way the notes sound, I miss the directness of the diatonic and most of all I miss that roughness and instability that the notes on the diatonic have.
Now that that is cleared up the other issue remains: why only one harp?
This requires a little more explanation I fear.
Before I explain I would like to point out that people ask me this question, but they don't ask someone who plays chromatic even though chroms are available in all keys just like diatonic harmonicas. These people seem to think that the diatonic somehow has notes missing or that some notes can't be played properly.
I again have to disagree because I believe that the diatonic does not have "missing notes" and this brings us to the first example:
If all the notes are there, does that mean that it is easy to play in all keys on one harp? No, it doesn't, some keys are very difficult indeed. So why don't I use different key harps then? I have a very clear reason to do so: I believe that I have to be able to play in 12 keys on one harp in order to play the music I want to play. Even if I only played in second position I would still need to be able to play in 12 keys on a single harp in order to play the type of jazz I play.
When I started out I just played on a single harmonica because I liked the challenge. As I got more interested in playing jazz I started to realize that the best way to learn to play all keys on a single harp is to actually keep on playing everything on a single harp. In the beginning this was very hard, but as the years progressed it became easier and at this time I find that it has become second nature to me.
So why do I think that in I need to be able to play in 12 keys in order to play jazz? Let me try and explain this by using two very common progressions in the jazz idiom. The first is the II-V progression and I have written out a line that is commonly used over the II-V in both first and second position.
example 1: II-V pattern in first position, C-harp
example 2: II-V pattern in second position, C-harp
In example 1&2 you see the use of the b9 on the dominant chord, this note is not part of the scale of the key but it is a note that is essential to playing jazz in these keys. What I want to show by this is that even in the most simple lines you need notes that lie outside the tonality you are playing in.
example 3: II-V pattern in first position, C-harp
example 4: II-V pattern in second position, C-harp
In example 3&4 you see the use of the altered dominant, something which is also very regularly used in many if not most jazz styles. The altered dominant not only implies a few notes that lie outside the tonality, it implies the use of a completely different scale. When playing over an altered dominant chord the scale that is used is derived from the melodic minor scale a half step up from the root of the chord. In example 3 the scale for the G7alt would be derived from Ab melodic minor. In example 4 the scale used for the D7alt would be derived from Eb melodic minor.
In most jazz styles these kind of temporary excursions outside the tonality occur regularly, not only as a result of altered chords but also as a result of chromatic embelishments. Now my point is this: if you play in first, second or any other position, you are going to need notes and scales that are derived from other keys/positions and in order to play them with accuracy and confidence you need to be familiar with them. How do you familiarize yourself with these keys/positions? You play them, preferably as often as possible.
In my opinion the best way to get used to playing far away positions is to treat them exactly like the lower positions and just play them. Avoiding them by changing harps is a sure way to not learn to play them.
If the only time you play Eb melodic minor is on the two beats that the D7alt chord lasts when you are playing in G, you will never learn it. However if you practice and play a tune that is in Eb minor and you do play it on a C-harp, then you will start to get a feel for that scale and the notes in it and when you need to use it in G it will not be a struggle but it will flow naturally.
Now there is one last question: why not play in 12 keys on every harmonica. why not learn to play 12 keys on a Bb harmonica and an Eb harmonica and an G harmonica etc..
That would be wonderfull. If you can pull it off I say go for it. I can't do it. Why? because of the intonation. Since the position of the mouth that is needed to play the bent and overblown notes differs between the different harmonicas I find it very difficult to play in tune on anything other than a C-harp. This is obviously a result of my longlasting commitment to the C-harp, but nevertheless this makes it very unpracticle for me to play on different harps.
I know that other people have far less problems with their intonation when switching harps and probably the same applies for this as for the playing in remote positions: the only way to learn is to do it. I would like to eventually learn to play a Bb and a low Eb harmonica, but at the moment I still have a lot of developing to do on the C-harp and until I feel that I have mastered the C-harp I don't want to get sidetracked by playing the Bb and Eb harps. There is also the fear that working on different key harps will adversely influence my intonation on the C-harp.