a South Dakota radio station
... that a South Dakota radio station once played nothing but various recordings of "Amazing Grace"?
... that <b id="mwA7g"><a class="mw-redirect" href="./KTPT" id="mwA7k" rel="mw:WikiLink" title="KTPT">a South Dakota radio station</a></b> once played nothing but various recordings of "<a href="./Amazing_Grace" id="mwA7o" rel="mw:WikiLink" title="Amazing Grace">Amazing Grace</a>"?