Free and forced oscillations are compared for infinite and bounded atmospheres. Both continuous and two layer bounded atmospheres are considered. It is found that bounded atmospheres reproduce the free oscillations of the infinite atmosphere with accuracy that depends on top height—they, however, also introduce spurious free oscillations. In studying forced oscillations, the spurious oscillations of bounded atmospheres appear as spurious resonances. In general, bounded atmospheres do not properly respond to oscillations that propagate vertically. Abstract Free and forced oscillations are compared for infinite and bounded atmospheres. Both continuous and two layer bounded atmospheres are considered. It is found that bounded atmospheres reproduce the free oscillations of the infinite atmosphere with accuracy that depends on top height—they, however, also introduce spurious free oscillations. In studying forced oscillations, the spurious oscillations of bounded atmospheres appear as spurious resonances. In general, bounded atmospheres do not properly respond to oscillations that propagate vertically.