An Introduction to Drawbars
|The Drawbars are the
heart and soul of the sound of your Hammond Organ. There are two sets of
nine Drawbars, sometimes referred to as Tonebars, for the Upper and Lower
Manuals and two Drawbars for the Pedals, located between the Upper Manual
and the Information Center Display.
Pulling a Drawbar out (towards you) will increase the volume in
incremental steps from 0 (no sound) to 8 (maximum volume). Pushing the Drawbar in
(away from you) decreases the volume of that Drawbar.
Your Hammond Organ has two sets of nine Drawbars, one for each manual.
Drawbars, often called Tonebars, are the heart and the basis of the renowned
Hammond Sound and have been used since the first Hammond Organ Model A
introduced in 1935.
There are approximately 253,000,000 possible sound combinations that can be
produced by these Drawbars. Each Drawbar consists of sine waves of different
pitches (which means tone depth). The illustration below shows how each
Drawbar relates to the manual when middle "C" is pressed.
Each Drawbar is marked with a number
followed by a footage mark. For example, the first white drawbar is marked
"8'". This is pipe organ terminology indicating that the pipe used to
produce the lowest note on the keyboard on a pipe organ is actually eight feet
long. The numbers from "1" to "8" on each Drawbar represent
degrees of loudness - number 1 being the softest, and number 8 being the
To take the fullest advantage of the harmonic Drawbars of the Hammond Organ,
it is necessary to understand what "music" really is.
All sounds, musical or otherwise are created by sending impulses or
vibrations through the air. These are "felt" in the sensitive
mechanism of our ears - a process we call "hearing". While you may
think that you hear a single individual sound, actually each sound, or musical
note, consists of a "fundamental" or basic tone, and a number of
"harmonics" or overtones - the latter being different when the same
note is played on different instruments.
For instance, when you play "A" above middle "C" on any
instrument - organ, piano, violin, trumpet, or any other - you are creating a
vibration at the rate of 440 impulses per second, provided of course that the
instrument is in proper tune. This is known as the "fundamental" of
this "A". However, the harmonics or overtones which accompany this
fundamental of "A" on the piano would be quite different from those
you would hear if you played the same note on, say, a violin or a trumpet.
This difference in harmonic structure is what distinguishes the sound of a
piano from that of a violin or another instrument, and is created by a
combination of differences in the materials and shape of the instrument, and
the manner of playing.
Now it is apparent that if you have available a source of sound which will
provide the fundamental sound of each note on the keyboard, plus a source of a
large number of harmonics, you are in a position to combine these fundamentals
and harmonics into musical tones similar to those of almost any instrument with
which you may be familiar. And that is just what the harmonic Drawbars of the
Hammond Organ do for you.
Drawbars are divided into 3 groups of sound as well as 3 groups of color.
We will first look at the 3 sound groups.
You may think of these sound groups in terms of the three levels - The Sub
being the deep pitches, the Foundation being the mid range of pitches and the
Brilliance being the high pitches.
Make sure all Drawbars are "IN" (off) and the Cancel
Touch Button is lit.
Hold down middle "C" on the Upper Manual.
Pull the first white Drawbar in the group of Drawbars for the
Upper Manual, marked "8'", all the way out.
While continuing to hold middle "C" down, pull the
first brown Drawbar in the group of Drawbars for the Upper Manual,
marked 16', all the way out. You will now hear the sound of
"C" one octave lower being added.
Now pull the second brown Drawbar in the same group out, and you
will hear it add a richness to the sound of the "C" note
that you are holding down.
Regardless of the size of a pipe organ or its number of stops, all of its
voices are related to four basic families of tone. The four basic families -
Flute, Reed, String and Diapason - can be quickly set up on the Drawbars by
relating a pattern or shape to each family.
These are the generalities which apply to the tonal resources of the
organ, and in themselves produce pleasant and usable effects. However, real
beauty of tone is secured in two ways. The first way is to use registrations
which have been devised by organists. The second way, and eventually the one
that best expresses your own feeling for the music, is to create your own
tonal effects, experimenting with and perfecting tones which you use to play
your favorite selections.
The Hammond Organ Drawbars allow you not only to set up any tonal effect
you want, but also to make many fine variations of the tone. Only with the
Hammond Drawbars can you play exactly the shade of tone you want for every
selection and, perhaps even more important, for every size and type of room
in which you play.
With the Hammond Organ Drawbars, a touch of a finger is all that is needed
to make the tone quality softer or more brilliant, richer in one harmonic or
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