G half-sharp
How a choir sings its way into G half-sharp.
Tuning
Home key, each time the loop comes round
G
+0.0¢
Right where the piano is.
About this toy
Jacob’s arrangement of In the Bleak Midwinter famously visits G half-sharp, a key that sits in the crack between two piano keys. One way a choir can get somewhere like that: pure tuning.
Each chord here is tuned perfectly, with none of the piano’s compromises, and every note two chords share is held dead still. Loop G - D - Am - Em and the whole choir rises about 21.5 cents per lap. That’s the syntonic comma. Two laps and a bit puts you a quarter-tone up.