Radial profiles of the Brunt-Väisälä frequency N in the ASH model (black) and the MESA model (dashed grey). The structural and chemical contributions to N_MESA, N_T, MESA, and N_μ, MESA, are represented in dotted-orange and dotted-dark-blue lines, respectively. The dashed green vertical line shows the boundary between the radiative zone and the convective envelope, while the grey hatched regions are excluded from the simulation domain. The frequency corresponding to the ray paths of Fig. 15 are represented by the solid horizontal red, blue, and yellow lines.