Census figures list Nashville as a "smaller" city than Memphis. But the Nashville area includes Murfreesboro, Franklin, Hendersonville, etc. making it much larger than Memphis. In fact, Nashville is the 30th largest DMA in the country.  By comparison, Chattanooga is 86th while Knoxville is 58th.  Even if Chattanooga bests Knoxville in population size, I agree, the Knoxville DMA will still be larger.