
noun – informal
realm: critical thinking Inability, or unwillingness to discriminate between what is true, right or important vs. what is irrelevant, desirable, or commonly accepted.
realm: music
Being tone deaf, or not possessing sensitivity to musical expression
Being insensitive to subtlety, value or appropriateness in words or thought.
Someone who does not easily relate to musical expression, i.e. that which is melodic, rhythmic, or tonal.
He has a tin ear for any new idea.