Here in the UK "Christian Music" as a genre isn't available in secular music stores and it doesn't get ANY airplay on national or local radio.
So you can't buy Jars of Clay or Michael W Smith or CeCe Winans next to Green Day, Eminem and Celine Dionne.
Hence I'd never heard any "Christian Music" until I left the JWs. LMAO at the hands over the ears bit, and you are right to deduce they are insane
As for "Kingdom Music" I would struggle to categorise it under "music" as the pianist on the tapes certainly couldn't read music well. If you follow the music to the kingdom songs you'll see that the pianist was playing the tunes by ear as he/she doesnt follow the music. No higher than a grade 4 musician I'd say