Book that's brilliant about popular music
I believe the answer is:
brighton rock
'book' is the definition.
(I've seen this before)
'popular music' is the wordplay.
'popular' becomes 'brighton' (I am not sure about this - if you are sure you should believe this answer much more).
'music' becomes 'rock' (rock is a kind of music).
'brighton'+'rock'='BRIGHTON ROCK'
'that's brilliant about' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for brighton rock that I've seen before include "... hard cylindrical sweet from the seaside" , "Hard tubular sweet from East Sussex" , "Book by Graham Greene" , "Film" , "What offers colourful writing all through" .)