Bit of music expected with boat race coverage (6)

I believe the answer is:

masked

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

'bit' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for masked that I've seen before include "Blocked out, disguised" , "With covered face" , "Unseen" , "Disguised, covered" .)

I've seen this clue in The Times and The Sunday 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.