Harmonica Techniques - Overbending

Overbending

In the 1970s, Howard Levy developed the "overbending" technique (also known as "overblowing" and "overdrawing".) Overbending, combined with bending, allowed players like Chris Michalek, Carlos del Junco, Otavio Castro and George Brooks to play the entire chromatic scale. When bending, the player forces the lower of the two reeds in a chamber to vibrate faster, while the higher pitched reed vibrates slower. When overbending, the player isolates the higher of the two reeds and by so doing can play higher pitched notes. By using both bending and overbending techniques a player can play the entire chromatic scale using a diatonic harmonica. This has allowed diatonic harmonica players to expand into areas traditionally viewed as inhospitable to the instrument such as Jazz.

The overbend is a difficult technique to master. To facilitate overbending, many players use specially modified or customised harmonicas. Any harmonica can be set up for better overbending. The primary needs are tight tolerances between the reed and reed-plate and a general level of air-tightness between the reed-plate and comb. The former often necessitates lowering the "gap", the space between the tip of the reed and the reed-plate. Another often used technique called embossing is to make the space between the sides of the slots in the reed-plate and the reed itself as small as possible by drawing in the metal on the sides of the reed-plate slots towards the reed. While these modifications make the harmonica overbend more easily, overbending is often possible on stock diatonic harmonica, especially on an airtight design.

Overblows Blow-Bends B♭ E♭ E♭ F♯ B♭ E♭ F♯ B C E G C E G C E G C <= Blow (1)(2)(3)(4)(5)(6) (7)(8)(9)(10) D G B D F A B D F A <= Draw C♯ F♯ B♭ C♯ A♭ C♯ A♭ C♯ F A A♭ Draw-bends Overdraws

Although there are players who use precise overbends and bends to play the diatonic harmonica as a fully chromatic instrument, this is still very rare, not simply because the technique is very difficult, but also because it requires an extreme level of skill, as well as a perfectly setup instrument, to match the tone of an overbend to the sound of other normally played notes. Thus, even though a player could play any melody in any key (within a three octave range) on a C diatonic harmonica, most harmonica players (especially those who focus on blues and/or diatonic harmonicas) prefer to match the possibilities of glissandos, register and dynamics of a given melody to a harmonica. Thus, the common practice is still to use different keys of diatonic harmonicas; recently some also use valved diatonics or XB-40 for different songs. As for harmonica players who play mostly classical or jazz music, most would rather use chromatics, as those styles call for a more fully chromatic style.

However, more and more people are attempting to overblow, or at least trying to bend on all notes (using valves or the XB-40), on diatonics, since overbend and bending allow wailing, which is a desired aspect of many styles such as blues — something that is hard to simulate with chromatic harmonicas.

The vibrato might also be achieved via rapid glottal (vocal fold) opening and closing, especially on draws (inhalation) simultaneous to bending, or without bending. This obviates the need for cupping and waving the hands around the instrument during play.