The theoretical spectrum of frequencies for the radial oscillations of a solar model is shown to depend on the treatment of convection near the model surface. For example, the period of the fundamental radial mode can vary from 48 minutes to 66 minutes, depending on the treatment. If the longest-period solar oscillation found by Hill, Stebbins, and Brown corresponds to the fundamental radial mode, then our understanding of the structure of the outer layers of the Sun has been considerably enhanced. (AIP)