This chapter aims to apply the results of earlier chapters to solar observations, considering both historical cases and recently obtained ground- or space-based observations of the Sun’s atmosphere. Coronal loops, prominences and sunspots are used to illustrate the various theoretical results. Attention to historical contributions is also part of the treatment. The founding of coronal seismology is explored and some results are applied to coronal loops. Results for resonant absorption theory are illustrated. Prominences are also explored from the viewpoint of oscillation theory, illustrating some results of prominence seismology. Finally, sunspots are discussed in the context of slow mode propagation.