Patreon Patron, Mr. Franklin, asks: “Dr. B – how about a post/lecture discussion about WHY certain composers or genres chose specific major or minor keys. To state the obvious, the intervals between the pitches in all major keys are the same whether the tonic is C or Ab. Why choose one over the other? Thanks.” This is an excellent question, one I am asked rather frequently. I would take this opportunity, then, to go on the record with response. To my mind, there are – different issues here: tuning systems; pitch levels; and the nature and physical demands of different musical instruments. Tuning Systems Ron Franklin correctly observes that in the equal tempered tuning system that is standard today, the intervals in all the major (and minor) keys are exactly the same. However, despite its adoption here and there during the late eighteenth and early nineteenth centuries, equal temperament did not become the gold standard, default tuning system in Europe until the mid-nineteenth century. The “system” that existed to that time was something called “well temperament”, which in fact is not a single tuning but rather, an umbrella term for various tunings in which certain keys were rendered incrementally brighter […]