You see the music on the page & see the notes on the piano-
You hear the notes being played and how they blend together -
You touch the keys and hands memorize shape for reaching different intervals-
You taste- you sing or speak the rhythms, words, counts, etc. -
You smell? This is a good one.
The other day at the commissary I smelled a mixture of cigarette smoke, Aqua net hair spray and Avon perfume. Now, to the average passerby that may not have been the most pleasant smelling experience, but to me it was heaven. My eyes started tearing up and memories of my grandmother "Granny" came flooding back to me even though she passed away 23 years prior.
Technically the musician does not "smell" music. But ask anyone who has taken lessons from someone w/ smelly breath or a smelly studio and I can guarantee you they remember that!
If there is a consistently pleasant smell around the piano or practice area, that smell will become part of the pleasant music/piano experience for the learner.
Voila--all 5 senses. So the biggest challenge is, next practice or lesson time, add a wonderful scent, take a breath mint, and make the musical experience as well-rounded as possible.