sentences:  WGRD made a number of formatic adjustments in the mid-1960s in response to its falling ratings, shifting to an adult contemporary format in 1964 and then to a Top 40/oldies mix the following year before tweaking back to Top 40 in 1967.WGRD reclaimed its market dominance after it added an FM signal at 97.9 MHz in 1971 (formerly WXTO), though AM 1410 was relegated to being a simulcast of the FM signal mornings and afternoons.For part of that time middays were "shadowcast."