Surprising announcement by King worried about revolutionary record label (9)
I believe the answer is:
bookplate
'label' is the definition.
(bookplate is a kind of label)
'surprising announcement by king worried about revolutionary record' is the wordplay.
I cannot quite understand how this works, but
'by' could be 'at' and 'at' is present in the answer.
'king' could be 'k' (chess abbreviation) and 'k' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for bookplate that I've seen is " Personal library label".)