Handel composition sung at British coronations (5,3,6)

I believe the answer is:

zadok the priest

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

'handel' is the definition.
Both the definition and answer are singular nouns.
Maybe you can see a link between them that I can't see?

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Another definition for zadok the priest that I've seen is " anthem".)

I've seen this clue in The Times.

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.