Half-exposed tenor at work? Not so (7)

I believe the answer is:

topless

I'm a little stuck... Click here to teach me more about this clue!

'half-exposed' is the definition.
I can't judge whether this definition defines the answer.

'tenor at work? not so' is the wordplay.
'tenor' becomes 't'.
'at' says to put letters next to each other.
'work?' becomes 'op' (abbreviation for opus).
'not so' becomes 'less' (eg 'not so big' means 'less big').
't'+'op'+'less'='TOPLESS'

Can you help me to learn more?

(Other definitions for topless that I've seen before include "Revealing" , "Bare from the waist up" , "Wearing no clothing above the waist" , "With chest totally exposed" , "Naked above the waist" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.