  It is currently impossible to determine the abundances and ages of the
stellar populations of distant, dense stellar systems star by star. Therefore,
methods to analyze the composite light of stellar systems are required. I
review the modelling and analysis of integrated spectra of the stellar
populations of individual globular clusters, globular cluster systems,
early-type galaxies, and the bulges of spiral galaxies, with a focus on their
abundances and abundance ratios. I conclude with a list of continuing
difficulties in the modelling that complicate the interpretation of integrated
spectra as well as a look ahead to new methods and new observations.

Astrophysics