The Hammond M-100 is a type of Hammond organ, produced by the Hammond Organ Company. The M-100 was smaller than the classic B-3 model, and is one of the smaller 'Spinet' organs. The Spinet organs are related to the larger B3 and C-3, but have shorter keyboards, built-in amplifiers, and fewer pedal options. These compact Hammonds are more portable, and were used by many famous musical groups and organists, due to their lighter weight and transportability for touring. The spinet Hammonds generate sounds by mechanical 'tonewheels' spinning inside the organ, just like the B3/C3 series of organs. While other organ companies used electronic oscillators or vibrating reeds to create notes, the Hammond tonewheel system creates a warm, rich sound that has become the classic organ sound of the 1960s and 1970s. The M-100's Vibrato/Chorus tone shares the same circuitry as the larger B3 and C3, so it is slightly superior to many other Hammond spinet models (like the L-100).