The Hammond Organ
Hammond Organ Invented by Laurens hammond in 1935.
Like the Telharmonium, it used mechanical means to create electronic signals of various frequencies.
Not a compact instrument.
Sound/Timbres were controlled by preset keys or manually through a series of drawbars.
Timbres were achieved as the fundamental and up to eight harmonics.
Each harmonic is added as its corresponding drawbar is pulled out.
A Hammond organ has two 61-key manuals (keyboards) and a 25-note pedal board.
Lower manual is called the great-Upper manual is called the swell.
Hammond Organ became very popular with jazz and rock groups in the 1970s such as Chicago; Emerson, Lake and Palmer; Jimmy Smith and has regained popularity in the last 10 years with Artists such as Medeski Martin and Wood, Joey Defrancesco and many current pop/rock artists.