Does YT say it is because of the music? Generally on mine they just say the monetization will go to the claimant (like BMG)
"A copyright owner using Content ID claimed some material in your video.
This is not a copyright strike. This claim does not affect your account status.
There are either ads running on your video, with the revenue going to the copyright owner, or the copyright owner is receiving stats about your video’s views."
"Claimed by: EDM (District)"
"Ad revenue has been paid to the copyright owner"
Hmm, I think so?