Recalling essence of George Michael, say, to cover musical rhythm (6)
I believe the answer is:
groove
'musical rhythm' is the definition.
(groove can mean the rhythm in a piece of music)
'recalling essence of george michael say to cover' is the wordplay.
'recalling' says the letters should be written in reverse.
'essence of' means to look at the middle letters.
'michael say' becomes 'Gove' (UK politician Michael Gove).
'to cover' is an insertion indicator.
The middle of 'george' is 'or'.
'or' back-to-front is 'ro'.
'ro' going within 'gove' is 'GROOVE'.
(Other definitions for groove that I've seen before include "Kind of furrow or rut" , "Long thin furrow" , "Long narrow furrow" , "What the hippies sought" , "in which needle was once employed?" .)