  The dynamics of a non-autonomous oscillator in which the phase and frequency
of the external force depend on the dynamical variable is studied. Such a
control of the phase and frequency of the external force leads to the
appearance of complex chaotic dynamics in the behavior of oscillator. A
hierarchy of various periodic and chaotic oscillations is observed. The paper
studies the structure of the space of control parameters. It is shown that in
the dynamics of the system there are oscillatory modes similar to those of a
non-autonomous oscillator with a potential in the form of a periodic function,
but there are also significant differences.
