Molar excess volumes, V(ijk)(E) and speeds of sound, U(ijk), of {2-methylaniline (i) + benzene (j) + methylbenzene (k)}, {2-methylaniline (i) + benzene (j) + 1,2-dimethylbenzene (k)}, and {2-methylaniline (i) + benzene (j) + 1,4-dimethylbenzene (k)} have been measured as a function of composition at a temperature of 308.15 K. The observed speeds of sound data have been utilized to determine excess isentropic compressibilities, k(S)(E) (ijk) of ternaries (i + j + k).