  The strange metallic regime across a number of high-temperature
superconducting materials presents numerous challenges to the classic theory of
Fermi liquid metals. Recent measurements of the dynamical charge response of
strange metals, including optimally doped cuprates, have revealed a broad,
featureless continuum of excitations, extending over much of the Brillouin
zone. The collective density oscillations of this strange metal decay into the
continuum in a manner that is at odds with the expectations of Fermi liquid
theory. Inspired by these observations, we investigate the phenomenology of
bosonic collective modes and the particle-hole excitations in a class of
strange metals by making an analogy to the phonons of classical lattices
falling apart across an unconventional jamming-like transition associated with
the onset of rigidity. By making comparisons to the experimentally measured
dynamical response functions, we reproduce many of the qualitative features
using the above framework. We conjecture that the dynamics of electronic charge
density over an intermediate range of energy scales in a class of strongly
correlated metals can be at the brink of a jamming-like transition.
