Baroque tuning.

I was listening an interview on KCRW with the director of a contemporary choir known as "Seraphic Fire." They produced a new recording of Claudio Monteverdi's Vespers with the composer's minimal arrangement. (Incidentally, this performance is selling very well on iTunes.)

To highlight the dramatic between a symphonic orchestra and Seraphic Fire, the host played both versions sequentially. I immediately noticed that the Seraphic Fire version was tuned down a half step. "That's the baroque tuning," I said out loud.

I thought this was a seemingly unimportant note, but my wife was taken aback and stared at me, bewildered, and asked: "How the hell do you do that? What's baroque tuning?"

Perfect pitch aside, I do know that baroque tuning is centered around A=415Hz, but that it's not just tuning everything down a half-step; the frequencies of each note are slightly different than the standard tuning (A=440hz) that is so common. Some Internet folk get quite technical about this.