Tentative approach (8)
I believe the answer is:
overture
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tentative approach</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 overture that I've seen before include "Introductory piece" , "Pre-curtain-up piece" , "Orchestral opener" , "Approach - musical introduction" , "Musical prelude to opera or ballet" .)