In a synthesizer or sampler, a method of relating a parameter to a control so that the degree to which the control effects the parameter can be adjusted. For example, a pitch-bend wheel might be scaled to produce a half-step bend for a given amount of movement, or it might be scaled tot give a whole octave. Nonlinear scaling between control and parameter will produce an output corresponding to some sort of curve. If there is a point on the curve where the output changes radically in response to input, this is often called a breakpoint. The scaling of keyboard parameters is called keyboard tracking.