text: The most revolutionary difference in the Hammond, however, is its huge number of tonewheel settings, achieved by manipulating a system of drawbars located near the manuals. By using the drawbars, the organist can combine a variety of electrical tones and harmonics in varying proportions, thus giving the Hammond vast registration. In all, the Hammond is capable of producing more than 250 million tones. This feature, combined with the three-keyboard layout (i.e., manuals and pedalboard), the freedom of electrical power, and a wide, easily controllable range of volume, made the first electronic organs more flexible than any reed organ, or indeed any previous musical instrument except, perhaps, the pipe organ itself.
  The classic Hammond sound benefits from the use of free-standing loudspeakers called tone cabinets. The sound is often further enhanced by rotating speaker units, usually manufactured by Leslie.
  The Hammond Organ was widely adopted in popular genres such as jazz, gospel, pop music, and rock music. It was utilized by bands such as Emerson, Lake, and Palmer, Booker T. & the M.G.'s, and Deep Purple, among others. Occasionally the legs would be cut off these instruments to make them easier to transport from show to show. The most popular and emulated organ in the Hammond line is the B3. Although portable "clonewheel organs" started to synthesize and displace the original Hammond tonewheel design in the 1970s, it is still very much in demand by professional organists. The industry continues to see a lively trade in refurbished Hammond instruments, even as technological advances allow new organs to perform at levels unimaginable only two or three decades ago.