I think the features which set off his 'sin' detectors are musical forms which originate outside of Europe, music which gives him personal pleasure (I feel he is frightened by his own body wanting to dance, when he says 'it makes the body want' he means 'it makes my body want') and music which reminds him he is rooted in flesh, listening with a body of flesh.
Anyway he's a bit like the Bill Bailey of theology.