Arnold tongues are parameter regions within which dynamics of a
mathematical model become mode-locked to a particular frequency or
period. Recent studies of models in a wide variety of fields (examples
include models of spiking in neurons, the human cardiorespiratory
system, a forced oscillator experiencing friction from a moving belt and
a DC/DC power converter) have identified Arnold tongues exhibiting a
curious geometry that is perhaps best likened to a string of sausages.
In this talk I will demonstrate how this structure may be understood in
piecewise-smooth continuous maps through symbolic dynamics and linear
algebra.