Classical dance form (6)
I believe the answer is:
ballet
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">classical dance form</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ballet that I've seen before include "Theatrical entertainment" , "Eg, Swan Lake" , "Nureyev's forte" , "Type of dance" , "Classical dancing style" .)