A study in quietude (5)
I believe the answer is:
etude
'a study' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for etude that I've seen before include "Indian statesman" , "Short piece of music for solo instrument" , "Chopin study" , "Testing musical composition" , "short musical piece" .)