We like to think that we all have common ground of a sort when we're explaining or teaching something in music. For example, if you think an octave is an octave everywhere, this little piece should disabuse you of that idea. I was catching up on my Scientific American 60 Second Science podcasts. One episode from September 25th was "Musical Note Perception Can Depend on Culture" which caught my attention. There was more to the piece but the headscratcher is that the Tsimane' people of Bolivia don't perceive two notes an octave apart as being the same note. They also do not find the tritone (augmented fourth interval, e.g. C and F#) unpleasant as most Westerners do, probably because culture embeds a musical structure in our brains; different cultures, different structures. What I take from this is that when you're going to teach, you should prepare yourself for communicating with a student who doesn't have the same cultural grounding that you had when you were at his/her stage of learning. The difference is unlikely to be this extreme but it doesn't take awfully much difference to create a barrier between how you teach and how they learn. Food for thought.