  Massless chiral fermions emergent in inversion symmetry-breaking Weyl
semimetals (WSMs) reside in the vicinity of multiple low symmetry nodes and
thus acquire strongly anisotropic dispersion. We investigate the longitudinal
electromagnetic modes of two-component degenerate Weyl plasma relevant to the
realistic band structure of type-I WSM. We show that the actual spectrum of
three dimensional collective density excitations in TaAs family of WSM is
gaples due to emergence of acoustic plasmons corresponding to out-of-phase
oscillations of the plasma components. These modes exist around the [001]
crystallographic direction and are weakly damped, thanks to large difference in
the Weyl velocities of the $W_1$ and $W_2$ quasiparticles when propagating
along [001]. We show that acoustic plasmons can manifest themselves as slow
beatings of electric potential superimposed on fast plasmonic oscillations upon
charge relaxation. The revealed acoustic modes can stimulate purely electronic
superconductivity, collisionless plasmon instabilities, and formation of Weyl
soundarons.
