Recording of trashy American boy band is something always left behind (7,4)
I believe the answer is:
kitchen sink
'recording of trashy american' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'boy band is something always left behind' is the wordplay.
I cannot quite understand how this works, but
'boy' could be 'itch' and 'itch' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for kitchen sink that I've seen before include "Down-to-earth (type of drama)" , "Sort of drama" , "Item in cookery area used to describe a type of drama" , "Place for washing up" , "Dramatically realistic" .)