Bending & Overblows

[BassHarper@xxxxxxx]

IMHO -

Richard Martin is correct when he states that "bending a reed" is merely a
term to describe a result, rather than a physical action.  A bend refers to
the pitch, not the reed itself.

BENDING NOTES
Certain notes are missing on the standard major-tuned diatonic harp.
 However, most of those notes can be found by what is referred to as
"bending" the reeds, a technique commonly used in playing blues and country.
 Bending is used mostly on draw notes (except holes 8, 9 & 10, which are blow
bends), and results
in flatting the note anywhere from 1/2 step (one semitone) to 1-1/2 steps
(three semitones).  To bend a note, start drawing gently on hole #3 until you
get a clear, clean tone.  Then drop your jaw slightly, and draw your tongue
back toward your throat.  (Saying the syllable "tah" will help with draw
bends.)  This will cause the note to flat, or bend.  With practice, you will
be able to control the amount of bend, and also you will be able to maintain
the pitch. 
Eventually it will be possible to play the exact bent note directly, without
having to bend down to it.  Care must be given to not draw too hard, as the
reed will not respond properly, and may even fatigue or fracture.  (Bending
notes fatigues reeds faster than playing straight harp.) 

MORE ON BENDING
Some notes will bend more than others, and some will bend only slightly,
depending on their relationship within the scale.  Bends are based on 1/2
step (one semitone) graduations, and are governed by the pitch of the other
reed within the same chamber.  The pitch of the higher reed can be bent down
to one semitone above the pitch of the lower reed.  Note that there is a
whole tone between C (blow) & D (draw) on hole #1 of a C major harmonica.
 This means that by drawing on hole #1, it is possible to bend D down 1/2
step (one semitone) to Db.  On hole #2, there are three semitones between E
(blow) and G (draw), so it is possible to bend the G draw down two semitones
to F# and F.  Hole #3 has four semitones from G (blow) to B (draw), allowing
bends of three
semitones from B to Bb, to A, to Ab.  Holes #4 & #6 have two semitones each
from blow to draw, allowing bends of one
semitone each.  Holes #8 thru #10 do not have draw bends, but rather have
blow bends.  Blow bends are done with the jaw slightly dropped, but with the
tongue forward, just behind the teeth.  (Saying the syllable "tee" will help
with blow bends.)  #8 will
bend one semitone (from E to Eb), #9 will bend one semitone (from G to Gb),
and #10 will bend two semitones (from C to B to Bb).In order for a draw reed
to bend, the blow reed in the same hole must be lower in pitch.  And for a
blow reed to bend, the draw reed in the same hole must be lower in pitch.
 The reason some notes will bend more than others, or only very slightly, is
that each reed is dependant on, and interacts with, the other reed in the
same
hole.  The greater the distance in pitch from one reed to the other in a
particular hole, the more bend is possible, as in hole #3.  Since there is
only one semitone difference between reeds in both holes #5 & #7, only a
slight bend is possible - less than one semitone each.

Though the above bending documentation is for a C Major harmonica, the
patterns are identical for all Major tuned harmonicas.

OVERBLOWS AND OVERDRAWS
A relatively new method of obtaining some of the "missing notes" has been
established and is being used by a growing number of advanced players.  It
has been given the descriptive name of "Overblow" and "Overdraw".  The effect
is that a given note is raised one semitone above the other note within the
same hole, using this method.  Example: on a C Major harmonica, hole #4 blow,
C, can be overblown to D# (one semitone above the draw reed), and hole #7
draw, B, can be overdrawn to C# (one semitone above the blow reed).  In order
to overblow, the draw reed must be higher in pitch than the blow reed in the
same hole.  And to overdraw, the blow reed must be higher in pitch than the
draw reed in the same hole.  Holes 4, 5 & 6 are easiest to overblow, but
theoretically overblows can be done with holes 1 thru 6, and overdraws can be
done with holes 7 thru 10.  Admittedly a difficult effect to achieve, it is
best reserved for the very advanced player.  Overblow and overdraw notes are
usually used only as passing notes, and are extremely difficult to sustain.
 They also usually lack a "pretty" tone, and sometimes are more of a squeal
or squeak by their very nature.