  The existence of non-q\bar{q} hadrons such as glueballs and hybrids is one of
the most important qualitative questions in QCD. The COMPASS experiment offers
the possibility to unambiguously identify such states and map out the glueball
and hybrid spectrum. In this review I discuss the expected properties of
glueballs and hybrids and how they might be produced and studied by the COMPASS
collaboration.
