I will discuss how holographic and effective
field theory methods could shed light on important
open questions in low energy condensed matter systems.
I will focus on the study of the vibrational degrees of freedom,
i.e. ''phonons'', in liquids, solids and disordered systems like glasses.
Building intuition from the holographic systems I will tackle the
problem of the low frequency elastic response in liquids and the
universal emergence of the boson peak in ordered crystals and
amorphous solids.