is a basic diatonic harmonica playing technique used to produce notes not otherwise available in the standard tuning of the harp, and to provide various sliding-note effects. Bends are, in large part, what give the diatonic harp its unique character, and are intimately related to the blues tradition.
Bends, whether draw bends or blow bends, produce notes lower in pitch than the natural, unbent note. I think that part of the "trick" to bending is knowing what note will result, and unconsciously anticipating that sound. If you think about singing for a second, paying attention to your vocal tract, when you sing a low note versus a high note your body sort-of automatically adjusts according to the pitch of the note. You get the note in your "mind?s ear" and your body tends to adjust without thinking about what you?re doing. Try to feel how there are more physical actions than merely your vocal cords buzzing at a different frequency. You tend to "sink" lower and open up "bigger" for singing low notes as opposed to high notes, and it?s similar for harp. What is happening is that your body is naturally adjusting to a shape that is more suitable to the pitch you know ahead of time you want to sing. Bending notes on the harp is much the same way. You have to adjust your vocal tract shape-the position of your mouth, tongue, jaw, throat, and soft palette, to be suitable for the pitch of the bent note. It?s easier to do that if you have a mental idea of what the note will sound like ahead of time. If you?ve never done bends before, that can be tough! How do you know what the note will sound like? It helps to play the note on another instrument, like a piano or guitar, to get it in your ear while you are working on trying to bend. Various computer programs can play different pitches, so that?s another way to try to get the pitch in your ear if you don?t have any other instruments available.
The amount you can bend a note depends on the pitches of the two reeds in the hole. The higher pitch note in the hole can be bent down to just above the lower pitch note in the hole. For example, the notes on a C harp in hole 2 are: blow-E, draw-G. The higher G note can be bent down to Gb and F--and just a little lower. It is best to only bend down to the desired note, and not further, in order to minimize stress on the reeds. When you practice your bends, it is good to use a piano, guitar, pitch pipe, electronic tuner or whatever to check that you're hitting the correct pitch.
Bending is not something that is easy to describe how to do-and it is difficult to show because all the movements are hidden inside the mouth and throat. It takes practice to be able to do bends at all, and lots more practice to do them well. Bends are the first major hurdle in playing the harp, and you should not expect to "get it" in a few minutes. It may take months. That?s okay. Don?t be in a hurry, and don?t get discouraged. If you keep at it, you?ll get it. You?re learning new control of your breath and your mouth, your breathing and your body?s resonance, your tongue and throat, and of your focus. Bends are something you?ll keep working on, probably for as long as you play the harp. Bends aren?t hard, but like anything else you have to get familiar with how to do it. You have to get familiar with how the harp responds to different vocal tract positions, and if you?re just starting you?re not yet familiar with how to set your mouth, tongue, and throat in different positions, much less particular positions needed to modify the air stream to produce different pitches. If you?re not "getting it" don?t get down on yourself! You just haven?t put in the practice to get familiar with what your need to do yet.
There are draw bends available on holes 1 through 6, and blow bends available on holes 7 through 10, each of which require different playing techniques. To make matters more interesting, different key harps require different bending techniques, depending on the pitch range of the harp. Lower key harps (e.g. A, Ab, G, and low F) require more mouth/throat/tongue (or simply "vocal tract") movement than the same holes on higher key harps (e.g. C, D, E, and F). Learning your bends not only gives you more notes and effects, it gives you more control over your notes, air stream, resonance, and tone.