Very musical (5)
I believe the answer is:
assai
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">very musical</span>' is the definition.<br/ ><span class="explanation-format__explanation">(musical term for 'very')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for assai that I've seen before include "Italian greatly contributed to score" , "Produced offspring" , "Very (in musical directions)" , "attack in concert, for the most part" , "small, purple, nutritional fruit" .)