What makes our tunings different from others?

There is a term in piano tuning called "temperament". It is most easily explained by comparing it to doing division and having a remainder. It is all how you spread out that remainder over the scale of the piano. Most piano tuners use what is called "equal temperament." This is where those numbers are all split exactly the same from every key to the next. This sounds good mathematically, but makes every key signature sound exactly like the next. Giving the piano a predictable and almost sterilized sound. Hassell's Piano Tuning uses what is called a "Well Temperament." The difference with this kind temperament is that different key signatures will have different "personalities." It is very similar in the way that J.S. Bach tuned his clavier in "The Well-Tempered Clavier." That is why composers chose certain keys for songs because different keys had different personalities. The keys of C, G and F are the most mellow. As one progresses through the circle of fifths adding either sharps or flats, each key will get progressively "crisper". You will hear a difference between the key of C and C#. You will find that it is much easier to pull emotion out of the music when your piano is tuned in a well temperament. You will also find that your piano has a larger and fuller sound.