The brain stem and the dorsal cochlear nucleus are able to distinguish between consonance (pleasing sounding note combinations) and dissonance ()unpleasant sounding nobe combinations). Human beings differ in what they fond consonant or dissonant and there is probably a neural basis for these preference. (Sternberg, Barbara, PhD. Music & the Brain. p 9-10. CA: Institute for Natural Resources, Home-Study #2320, 2009).