Music to make nanny’s companion seriously disturbed? (10)

I believe the answer is:

rockabilly

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

I can't explain the rest of the clue.

(Other definitions for rockabilly that I've seen before include "Type of music" , "notes of the 1950s" .)

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.