The Drawbars
You’ve heard the expression, "Pulling out all the stops?" The drawbars on the organ are these very stops. The organist can "voice" each stop as he plays. Meaning, any one of the nine drawbars that go into the makeup of an organ sound can be individually altered, either while playing, or permanently preset into one of the 9 preset keys. (The other three are for setting or clearing the presets.) Each drawbar has eight degrees to which it can be literally "drawn" or pulled, out of the console of the organ, the eighth being the loudest, and all the way in being silence. The nine drawbars represent the nine most important harmonics, going in order of left to right, the sub-octave, the fifth, the unison or fundamental octave, the 8th, the 12th, the 15th, the 17th, the 19th, and the 22nd. All of these except the 17th are either roots or fifths. The 17th is a third. The colors on the drawbars themselves are also related to their harmonic pitch. The white and brown drawbars are called the consonants, all the roots and the lower fifths, and the black drawbars are called the dissonants, the higher fifths and the third. Using this basic harmonic series, almost any instrumental tone may be imitated or mimicked. Also, the inventor of the Hammond organ, Laurens Hammond, who invented the B-3 around 1937-39, and who later unveiled it at the 1939 AES show here in New York City at the RCA building, used some of his father’s techniques, who happened to be a designer of pipe organs, in the development of his new organ. The drawbars are all labeled to represent pipe pitches, represented by length, ranging in order of largest to smallest, from left to right. These "lengths" are, 16', 8', 5 1/3', 4', 2 2/3', 2', 1 3/5', 1 1/3', and 1', being the smallest. By the way, the two drawbars for the pedals are called the Super-Octave and the Sub-Octave, and their respective "lengths" are 16' and 8'. Just like the fundamentals for creating sound waves lies in harmonics, (much like what we have learned in this class,) such is the way with the drawbars and their harmonic series. For instance, in terms of sound waves and frequency, the 1st harmonic by itself creates a sine wave, or a flute/recorder-type sound. The odd harmonics create a square wave, or a clarinet-like sound. The odd harmonics "squared" create a triangle wave, or a string-like sound. And all harmonics together create a sawtooth wave, or an oboe-like sound. Drawbar settings use the same kind of premise; various levels and volumes of harmonics are used to create sounds. There are literally millions of tone qualities and endless shades of dynamic level available on the Hammond organ. Figure 1, (see back pages), or drawbar setting (00 6200 000) is an example of a flute tone. Figure 2 (00 4345 554) is an example of a violin tone. Figure 3 (00 6876 540) is an example of a trumpet-like tone, and Figure 4 (54 5444 222) is an example of a diapason, or a typically organ-like tone quality. There are also the typical jazz settings (not included in the appendix,) such as 88 8000 000, the most common, used by jazz players 90% of the time, 88 8400 080, for a bit more of a whistle during solos, 80 0000 088, for a high-end chordal voice setting, or the full blown 88 8888 888, the largest sound possible on the organ, which is used usually for loud chord solos, or huge crescendos or climaxes. That particular setting truly defines the phrase "pulling out all the stops", and it means exactly what it says; the works. Of course, there are a multitude of other possibilities, and every player out there has his or her own particular setting, or 'sound'. But how exactly do the drawbars do what they do? The answer to that lies in the tone generator.
