Sound material for notes together (5)
I believe the answer is:
chord
'sound material' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for chord that I've seen before include "Notes struck together" , "'The Lost - - ' (Sullivan)" , "line for mathematicians" , "Group of notes in harmony" , "Number of notes played together" .)