Confused tale about key part of shoelace (5)
I believe the answer is:
aglet
'part of shoelace' is the definition.
('aglet' is part of 'shoelace')
'confused tale about key' is the wordplay.
'confused' indicates anagramming the letters.
'about' means one lot of letters goes inside another.
'key' becomes 'g' (musical key).
'tale' with letters rearranged gives 'alet'.
'alet' going around 'g' is 'AGLET'.
(Other definitions for aglet that I've seen before include "Tag at end of a shoelace" , "Metal tag on shoelace" , "Tube at end of shoelace" .)