Crossword Genius

Singer lacking note, goes off (3,4,4)

Ross

I believe the answer is:

nat king cole

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

'singer' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Another definition for nat king cole that I've seen is " singer".)

I've seen this clue in The Hindu.
Want a hint initially instead of a full solution? Install my app