[devmacrile]

In his lecture series on Bach, Robert Greenberg discusses temperament quite a bit and I found it fascinating. He relays all these descriptions that Bach had of different keys that are basically lost on us now as we cannot refer to the specific tunings he utilized (and thus cannot hear a lot of the music he wrote as he wrote it).

He also makes the claim that equal temperament became wide spread _because_ of the piano specifically - not just to sound the same in every key, but to sound the same on each piano. And so equal temperament would not have saturated European music until the early 19th century when the piano became ubiquitous. The reason being (as mentioned) that many other instruments can be tuned by the musician on the spot, whereas a piano requires some standardization.