Associate Professor of Music (and director of the Kalamazoo Philharmonia) Andrew Koehler shows that the countless possibilities of musical expression and mood share a common source and beautiful unity composed of a mere twelve notes. Composers, often in homage to pre-existing material (a few notes in a specific sequence, for example) build infinite variations and whole new worlds of feeling to which lifelong students like Koehler devote entire lifetimes of study and passion.