Pure, holy band is playing Gershwin piece (8,2,4)

I believe the answer is:

rhapsody in blue

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

'gershwin piece' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'pure holy band is playing' is the wordplay.
'playing' indicates an anagram.
'pure'+'holy'+'band'+'is'='pureholybandis'
'pureholybandis' anagrammed gives 'RHAPSODY IN BLUE'.

Can you help me to learn more?

(Other definitions for rhapsody in blue that I've seen before include "Gershwin's piece" , "Example of jazz" .)

I've seen this clue in The Everyman puzzle in The Observer.

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.