Correct! Most live performed music does not use equal-temperament. Many keyboard instruments do not use equal-temperament either, especially organs/clavichords

Correct! Most live performed music does not use equal-temperament. Many keyboard instruments do not use equal-temperament either, especially organs/clavichords etc. One of the interesting things about organ tunings is that because you can choose which pipes to perform with, different pipe-sets may be tuned according to slightly different needs on the same instrument. So, you might have one set of pipes that is well suited for equal-tempered, highly chromatic pieces. Another set of pipes may be intended for use with choirs, and another set still tuned to be ideal in an orchestral setting. However, the specific tuning of the instrument is usually maintained over the course of its life, which is part of why organs can be so distinct and characteristically themselves. Most organs are tuned by ear with tooling assists, and generally land in a Wohltemperiert that compromises between equal-temperament and pure 5ths. Pure 5ths are are especially important on an organ, because many of the pipes produce highly sinusoidal fundamentals, making un-pure 5ths especially obvious and "out of tune" sounding. The complexity and bloom of the harmonics in a piano helps to mask these effects.