Song opener recalled in study, lavatory and shed (3,3,4,4)

I believe the answer is:
dye ken john peel
'song opener recalled in study' is the definition.
I know nothing about this answer so I can't judge whether this works.
'lavatory and shed' is the wordplay.
I cannot quite understand how this works, but
'lavatory' could be 'john' (synonyms) and 'john' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
'shed' could be 'peel' (I've seen this in another clue) and 'peel' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dye ken john peel that I've seen before include "hunting song?" , "Are you aware of DJ" .)
