City celebrity interrupted by steel band at first (6)
I believe the answer is:
lisbon
'city' is the definition.
(Lisbon is an example)
'celebrity interrupted by steel band at first' is the wordplay.
'celebrity' becomes 'lion' (both can mean a celebrated person).
'interrupted by' is an insertion indicator.
'at first' suggests taking the first letters.
The initial letters of 'steel band' is 'sb'.
'lion' going around 'sb' is 'LISBON'.
(Other definitions for lisbon that I've seen before include "Portuguese capital" , "European capital" , "Capital city and Treaty" , "Portugal's capital" , "Capital of Portugal" .)