An embellishment or grace (marked thus, /), commonly
   consisting of the principal note, or that on which the turn is made,
   with the note above, and the semitone below, the note above being
   sounded first, the principal note next, and the semitone below last,
   the three being performed quickly, as a triplet preceding the marked
   note. The turn may be inverted so as to begin with the lower note, in
   which case the sign is either placed on end thus /, or drawn thus /.