Picked up a tie -- it's worn by a performer (4)
I believe the answer is:
tutu
'worn by a performer' is the definition.
I can't judge whether this defines the answer.
'picked up a tie it's' is the wordplay.
'picked up' says the letters should be written in reverse.
'a tie' becomes 'utu' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'utu'+'t'='utut'
'utut' in reverse letter order is 'TUTU'.
Can you help me to learn more?
(Other definitions for tutu that I've seen before include "Ballerina's costume" , "Short skirt for ballet dancer" , "Ballet-dancer's skirt" , "Ballet dancer's costume" , "very short garment" .)