I believe the answer is Participle Phrase.
Here are Google's definitions of "fluting".
noun
<span>1. sound reminiscent of that of a flute.
"the silvery fluting of a blackbird"
2. a groove or set of grooves forming a surface decoration.
"a hollow stem with vertical flutings"
</span>adjective
1 .reminiscent of the sound of a flute."the golden, fluting voice filled the room"
