"She sells seashells down by the sea shore" was taught to us in Elocution Class way back in the 1930s and 40s to improve our diction.
SHucks, just call up SOED CD and there's a hundred of them.
BTW is it just me or has diction totally dropped out of the skills required for singers? I rarely understand lyrics these days but any old recording by Bing, Dinah Shoe, any movie with Doris Day or Kathryn Grayon, Deanna Durbin and you can understand every word. It adds to the enjoyment to know what the singer is singing about, doncha think?
wow