Special Tunings

Harmonicas with special tunings have reeds that have been tuned differently from the standard for that instrument, e.g. Richter major diatonic tunings for diatonic harps, and solo tuning for chromatics.  There are a few common special tunings for the diatonic harp, and hundreds of rare ones have been designed.  (See Pat Missin's comprehensive collection of special tunings in his "Altered States" document at http://patmissin.com/tunings.html).

Special tunings offer different natural notes (unbent blows and/or draws) from the standard tuning.  These different natural notes create different chords, and can be beneficial for playing songs or melodies that need the new note more than the one it replaced, and suffer from producing the note via bends or overbends.  Special tunings differ from the standard tuning by as little as one note (e.g. the country tuning) and as many as all of them!  (Some players, for example, tune a normal C harp up to a standard D tuning.)  Since the available bends and overbends depend on the pitches of the natural notes in the hole, special tunings have different bending capabilities and bend notes than the standard tuning, in addition to different natural notes.

The best bet is to try some of these special tunings to hear their characteristics sounds and feel their different playing characteristics.  These tunings can bring new music into your repertoire and help bust you out of playing ruts, since your same ol' licks will sound new and fresh with the different notes and chords.

Country Tuning

The country tuning, also called the "jazz" tuning for Huang brand harps, is the simplest and one of the most common special tunings.  The only difference from a standard Richter major diatonic tuning is that the hole 5 draw note is raised a semitone--e.g. from a Bb to a B on an F harp, or F to F# on a C harp, that's it, just one reed is tuned differently.  This is very useful in many songs whose melodies use the major 7 note of the root chord in second position--e.g. C on an F harp, or G on a C harp.  On a standard tuning, that note requires an overblow on hole 5, which is not a simple note to play well.  Further, many such songs are harmonized with a Major 7 root chord rather than a dominant 7 chord found on the standard tuning (e.g. CMaj7 instead of C7), and that chord change occurs as well--the second position root chord becomes a Maj7 instead of a 7 chord.  In addition, the V chord for 2nd position (G in key of C) is now major instead of minor, changing the feel of the 4/5/6 draw chord as well as the 2/3/4/5 draw chord.

The effect of raising the pitch of the 5 draw a half step is to add a draw bend to hole 5--on a normal tuning the hole 5 draw bend is less than a full semitone (i.e. "missing")--which is the same note as the natural hole 5 draw on a standard tuning.  In other words, you don't lose that note because you raise the pitch of its reed a half step--it just moves to a new bend in hole 5' that is easy to hit (i.e. it's not a "fretless" bend like 2' or 3").  Here's the layout for second position key of C with the country tuning changes highlighted:

 

Melody Maker(TM) Tuning (Lee Oskar(TM)  Harmonicas)

The Melody Maker tuning takes the country tuning one step farther and changes the pitch of 3 reeds from the standard tuning.  In addition to raising hole 5 draw a half step to the major 7 note of the 2nd position scale, e.g. Bb to B on a key of C Melody Maker (which are labeled based on 2nd position), it also raises the octave of the 5 draw, the 9 draw, a half step from Bb to B on a C Melody Maker.  So both the 5 draw and the 9 draw are raised a half step.  In addition, the pitch of the hole 3 blow is raised a whole step.  This means the hole 3 blow is no longer the same note as the hole 2 draw.  You lose the corresponding 2 bend notes for the hole 3 draw, i.e. the whole step and step-and-a-half bends (D and Db for 2nd position C).  Note that this also pushes the Db from a bend in hole 3 to an overblow in hole 2, and the Bb from a bend in hole 9 to an overblow on hole 8.  The blow chords on the low end of the harp change as you get a 6th flavor in blow 1/2/3 (e.g. F/A/D), and a minor chord in 3/4/5 (e.g. D/F/A).  Along with the Maj7 for the root chord (instead of dominant 7), and 2  major V chords (insteand of minor) at 4/5/6 and 8/9/10, the chordal feel of this tuning is quite different from a standard tuning, perhaps more "pop" sounding than a standard tuning which works better for blues and rock feel.  Here's a key of C diagram with the differences highlighted:

Natural Minor Tuning

The natural minor tuning (or essentially similar dorian minor "mol n" tuning) changes the character of the diatonic, as its name implies, from a major feel to a minor feel.  Five reeds have their notes changed: the blow 2, 5, and 7 notes are flatted a half step, e.g. from A to Ab on a 2nd position C tuning, and the draw 3 and 7 notes are also flatted a half step, e.g. from E to Eb on a 2nd position C tuning.  The bends and overblows change according to the changes of these natural notes.  In first position the natural mode is a dorian minor, while in second position the natural mode is a natural minor.  The blow chords, which are major on a standard tuning, are minor (flat third) in this tuning, and the normally major draw chord in (1)/2/3/4 is now also a minor chord.  This minor 3rd of the 2nd position scale is a primary "blue" note often used in blues (but in blues the note is often between a major and a minor third, not bent all the way flat).  Many minor key songs lay out more naturally on a natural minor tuning than on a standard Richter major tuning.

Harmonic Minor Tuning

The harmonic minor tuning has a harmonic minor scale as the natural mode of first position play.  As in the natural minor tuning, 5 reeds have changed notes: the musical 3rds are flatted by lowering blow notes in holes 2, 5, and 8 a half step and the draw notes in holes 6 and 10 are also lowered a half step to provide the flat 6th for the harmonic minor scale.

Steve Baker Special

The Steve Baker Special (SBS) is both a special tuning and a special harp--14 holes instead of 10, but the very top hole is "extra" and not really part of the tuning.  The Steve Baker Special basically just duplicates the first 3 holes of a standard tuning as the first 3 holes of the SBS, and keeps the rest the same.  For keys above A, the bottom 3 holes are an octave lower than a standard tuning.  This tuning provides an extra set of good bending draw reeds for blues, and is particularly good for vamping chords on the low end while mixing in melody above.  Here is a look at a key of C SBS tuning:

 

Hohner 365

The Hohner 365 is another 14 hole diatonic harp.  It is similar to the Steve Baker Special only instead of duplicating the first 3 holes as the lower octave, the Richter major diatonic pattern is held consistent as 4 more holes are added to the high end of a standard Richter major diatonic layout.   This means that the bottom 10 holes are like a "tenor" or low tuned standard diatonic, and the high 4 holes are "all messed up", but add interesting possibilities, especially for blow bends.  Here are holes 11-14 on a Hohner 365:
Hole 11 12 13 14
Draw B D F A
Blow E G C E
Hohner 365

Combination Tuning

Invented by Winslow Yerxa (as far as I know), this tuning provides a combination of seconnd position (low end) and first position (high end) bends to try to optimize the harp for playing blues.  Here's how it looks:

Other Tunings

There are other special tunings commercially available, or able to be produced by you or your favorite harp technician.  Some harmonica companies (e.g. Hering and Suzuki) will even make harps tuned to your specification for an extra charge.  These include the Spanish tuning, spiral tuning, and various layouts based on whole tones (augmented triads) that provide full chromatic capabilities to the diatonic harp by using only normal bends, with no overbends or valved bends required.  These are used much less frequently than the above, usually for special songs or playing requirements, or just to explore the capabilities of the harp.  Amazingly enough, since the Richter layout was not designed with bends and overblows in mind, none of these exotic tunings or even the normal special tunings, has superior general applicability to the Richter major tuning to displace it as the tuning of choice for the vast majority of players.  As overblows become more accessible to a wider range of players, the biggest advantages of special tunings is in their chordal capabilities for certain songs and styles of music.

Magic Dick Tunings

The famous harp player for the J. Geils band, "Magic" Dick, has worked with Pierre Beaurigard to patent the whole range of diatonic tunings where the blow note is always lower than the draw note, and all bends are draw bends.  Some of these tunings should become commercially available in the forseeable future.  Companies that offer custom special tunings may be resistent to the potential of infringing on this patent.