  The excitation spectrum of light mesons, which are composed of up, down, and
strange quarks, is studied since decades. However, it still holds a number of
puzzles and surprises that provide new insights into the nature of the strong
interaction. Recent high-quality data samples from several experiments allow us
to not only study the properties of established mesons with unprecedented
precision but to also search for new states. These searches aim in particular
at resolving the question of the existence of so-called exotic states, such as
four-quark states or states with excited gluon fields. Since light mesons have
often large widths and are overlapping, the mapping of their spectrum is
challenging and requires large quantities of data on different production and
decay modes. The data are analyzed using a framework of interfering quantum
mechanical amplitudes known as partial-wave analysis (PWA). Most excited meson
states decay into multi-particle final states, for which the PWA requires
extensive modeling of the dynamics of the final-state hadrons. I will give an
overview on ongoing experimental studies of light mesons and discuss possible
interpretations. I will also touch on novel analysis techniques and the
prospects for future progress.
