  This paper reviews non-resonant, meV-resolution inelastic x-ray scattering
(IXS), as applied to the measurement of atomic dynamics of crystalline
materials. It is designed to be an introductory, though in-depth, look at the
field for those who be may interested in performing IXS experiments, or in
understanding the operation of IXS spectrometers, or those desiring a practical
introduction to harmonic phonons in crystals at finite momentum transfers. The
treatment of most topics begins from ground-level, with a strong emphasis on
practical issues, as they have occurred to the author in two decades spent
introducing meV-resolved IXS in Japan, including designing and helping to build
two IXS beamlines, spectrometers and associated instrumentation, performing
experiments, and helping and teaching other scientists. After an introduction
that compares IXS to other methods of investigating atomic dynamics, some of
the basic principles of scattering theory are described with the aim of
introducing useful and relevant concepts for the experimentalist. That section
includes a fairly detailed discussion of harmonic phonons. The theory section
is followed by a brief discussion of calculations and then a longer section on
spectrometer design, concepts, and implementation, including a brief
introduction to dynamical diffraction and a survey of presently available
instruments. Finally, there is discussion of the types of experiments that have
been carried out, with a focused discussion on measurements of superconductors,
and brief discussion (but with many references) of other types of crystalline
samples.
