a pipe organ has one or more keyboards (called "manuals") played by the hands, and a pedalboard played by the feet; each keyboard controls its own division, or group of stops. the keyboard(s), pedalboard, and stops are housed in the organ's "console". the organ's continuous supply of wind allows it to sustain notes for as long as the corresponding keys are pressed, unlike the piano and harpsichord whose sound begins to dissipate immediately after a key is depressed. the smallest portable pipe organs may have only one or two dozen pipes and one manual; the largest may have over 33,000 pipes and seven manuals. a list of some of the most notable and largest pipe organs in the world can be viewed at list of pipe organs. a list consisting the ranking of the largest organs in the world - based on the criterion constructed by michał szostak, i.e. 'the number of ranks and additional equipment managed from a single console - can be found in 'the organ' and in 'the vox humana'.