  This paper reviews non-resonant meV-resolved inelastic x-ray scattering (IXS)
as a complementary method to inelastic neutron scattering (INS). Two aspects of
IXS that are notable in this context are (1) that IXS allows straightforward
measurements of phonons in small (sub-mm, and even $\sim 0.01$ mm) samples with
$\sim 1$ meV resolution and excellent Q resolution and (2) that IXS avoids the
kinematic constraints of INS. The first allows both new geometries (thin films,
diamond anvil cells) and easy access to new materials, while the second allows
high quality data on disordered materials, such as scans with sub-meV
resolution to arbitrarily high energy transfer become possible , even at
momentum transfers as small as 1/nm. The review briefly discusses the
spectrometers and compares the practical forms for the dynamic structure factor
for crystals, glasses and liquids. This is followed by a longer review of work
on liquids and then shorter discussion of work on glasses, crystals, and
discussion of specific geometries. This paper complements the longer
introduction/review of IXS at arxiv:1504.01098 .
